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Algebra and Trigonometry

Robert Blitzer

Chapter 8

Systems of Equations and Inequalities - all with Video Answers

Educators

AG

Section 1

Systems of Linear Equations in Two Variables

01:11

Problem 1

Determine whether the given ordered pair is a solution of the system.
$(2,3)$
$\left\{\begin{array}{l}{x+3 y=11} \\ {x-5 y=-13}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:20

Problem 2

Determine whether the given ordered pair is a solution of the system.
$(-3,5)$
$\left\{\begin{array}{l}{9 x+7 y=8} \\ {8 x-9 y=-69}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:13

Problem 3

Determine whether the given ordered pair is a solution of the system.
$(2,5)$
$\left\{\begin{array}{r}{2 x+3 y=17} \\ {x+4 y=16}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:24

Problem 4

Determine whether the given ordered pair is a solution of the system.
$(8,5)$
$\left\{\begin{array}{l}{5 x-4 y=20} \\ {3 y=2 x+1}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
00:55

Problem 5

Solve each system by the substitution method.
$\left\{\begin{array}{l}{x+y=4} \\ {y=3 x}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:01

Problem 6

Solve each system by the substitution method.
$\left\{\begin{array}{l}{x+y=6} \\ {y=2 x}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:45

Problem 7

Solve each system by the substitution method.
$\left\{\begin{array}{l}{x+3 y=8} \\ {y=2 x-9}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:44

Problem 8

Solve each system by the substitution method.
$\left\{\begin{array}{l}{2 x-3 y=-13} \\ {y=2 x+7}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:20

Problem 9

Solve each system by the substitution method.
$\left\{\begin{array}{l}{x=4 y-2} \\ {x=6 y+8}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:15

Problem 10

Solve each system by the substitution method.
$\left\{\begin{array}{l}{x=3 y+7} \\ {x=2 y-1}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:05

Problem 11

Solve each system by the substitution method.
$\left\{\begin{array}{r}{5 x+2 y=0} \\ {x-3 y=0}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:08

Problem 12

Solve each system by the substitution method.
$\left\{\begin{array}{l}{4 x+3 y=0} \\ {2 x-y=0}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:38

Problem 13

Solve each system by the substitution method.
$\left\{\begin{array}{l}{2 x+5 y=-4} \\ {3 x-y=11}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:38

Problem 14

Solve each system by the substitution method.
$\left\{\begin{array}{c}{2 x+5 y=1} \\ {-x+6 y=8}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:32

Problem 15

Solve each system by the substitution method.
$\left\{\begin{array}{l}{2 x-3 y=8-2 x} \\ {3 x+4 y=x+3 y+14}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:39

Problem 16

Solve each system by the substitution method.
$\left\{\begin{array}{l}{3 x-4 y=x-y+4} \\ {2 x+6 y=5 y-4}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:29

Problem 17

Solve each system by the substitution method.
$\left\{\begin{array}{l}{y=\frac{1}{3} x+\frac{2}{3}} \\ {y=\frac{5}{7} x-2}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:05

Problem 18

Solve each system by the substitution method.
$\left\{\begin{array}{l}{y=-\frac{1}{2} x+2} \\ {y=\frac{3}{4} x+7}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:30

Problem 19

Solve each system by the addition method.
$\left\{\begin{array}{l}{x+y=1} \\ {x-y=3}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:22

Problem 20

Solve each system by the addition method.
$\left\{\begin{array}{l}{x+y=6} \\ {x-y=-2}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:09

Problem 21

Solve each system by the addition method.
$\left\{\begin{array}{l}{2 x+3 y=6} \\ {2 x-3 y=6}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:11

Problem 22

Solve each system by the addition method.
$\left\{\begin{array}{l}{3 x+2 y=14} \\ {3 x-2 y=10}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:34

Problem 23

Solve each system by the addition method.
$\left\{\begin{aligned} x+2 y &=2 \\-4 x+3 y &=25 \end{aligned}\right.$

AG
Ankit Gupta
Numerade Educator
03:10

Problem 24

Solve each system by the addition method.
$\left\{\begin{array}{l}{2 x-7 y=2} \\ {3 x+y=-20}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:52

Problem 25

Solve each system by the addition method.
$\left\{\begin{array}{l}{4 x+3 y=15} \\ {2 x-5 y=1}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:11

Problem 26

Solve each system by the addition method.
$\left\{\begin{array}{l}{3 x-7 y=13} \\ {6 x+5 y=7}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:54

Problem 27

Solve each system by the addition method.
$\left\{\begin{array}{l}{3 x-4 y=11} \\ {2 x+3 y=-4}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:44

Problem 28

Solve each system by the addition method.
$\left\{\begin{array}{l}{2 x+3 y=-16} \\ {5 x-10 y=30}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:03

Problem 29

Solve each system by the addition method.
$\left\{\begin{array}{l}{3 x=4 y+1} \\ {3 y=1-4 x}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:31

Problem 30

Solve each system by the addition method.
$\left\{\begin{array}{l}{5 x=6 y+40} \\ {2 y=8-3 x}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:31

Problem 31

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{x=9-2 y} \\ {x+2 y=13}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:03

Problem 32

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{6 x+2 y=7} \\ {y=2-3 x}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:05

Problem 33

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{y=3 x-5} \\ {21 x-35=7 y}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:34

Problem 34

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{9 x-3 y=12} \\ {y=3 x-4}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:07

Problem 35

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{3 x-2 y=-5} \\ {4 x+y=8}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:17

Problem 36

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{2 x+5 y=-4} \\ {3 x-y=11}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:29

Problem 37

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{r}{x+3 y=2} \\ {3 x+9 y=6}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:38

Problem 38

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{4 x-2 y=2} \\ {2 x-y=1}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:30

Problem 39

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{\frac{x}{4}-\frac{y}{4}=-1} \\ {x+4 y=-9}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
View

Problem 40

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{\frac{x}{6}-\frac{y}{2}=\frac{1}{3}} \\ {x+2 y=-3}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
04:16

Problem 41

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{2 x=3 y+4} \\ {4 x=3-5 y}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
04:07

Problem 42

Solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
$\left\{\begin{array}{l}{4 x=3 y+8} \\ {2 x=-14+5 y}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
01:45

Problem 43

The sum of two numbers is 7 . If one number is subtracted from the other, their difference is $-1 .$ Find the numbers.

AG
Ankit Gupta
Numerade Educator
01:43

Problem 44

The sum of two numbers is $2 .$ If one number is subtracted from the other, their difference is $8 .$ Find the numbers.

AG
Ankit Gupta
Numerade Educator
02:33

Problem 45

Three times a first number decreased by a second number is 1. The first number increased by twice the second number is 12. Find the numbers.

AG
Ankit Gupta
Numerade Educator
02:28

Problem 46

The sum of three times a first number and twice a second number is 8. If the second number is subtracted from twice the first number, the result is 3. Find the numbers.

AG
Ankit Gupta
Numerade Educator
03:18

Problem 47

Solve each system by the method of your choice.
$\left\{\begin{array}{l}{\frac{x+2}{2}-\frac{y+4}{3}=3} \\ {\frac{x+y}{5}=\frac{x-y}{2}-\frac{5}{2}}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
03:16

Problem 48

Solve each system by the method of your choice.
$\left\{\begin{array}{l}{\frac{x-y}{3}=\frac{x+y}{2}-\frac{1}{2}} \\ {\frac{x+2}{2}-4=\frac{y+4}{3}}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:29

Problem 49

Solve each system for $x$ and $y,$ expressing either value in terms of a or $b$, if necessary. Assume that $a \neq 0$ and $b \neq 0.$
$\left\{\begin{array}{r}{5 a x+4 y=17} \\ {a x+7 y=22}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:10

Problem 50

Solve each system for $x$ and $y,$ expressing either value in terms of a or $b$, if necessary. Assume that $a \neq 0$ and $b \neq 0.$
$\left\{\begin{array}{l}{4 a x+b y=3} \\ {6 a x+5 b y=8}\end{array}\right.$

AG
Ankit Gupta
Numerade Educator
02:12

Problem 51

For the linear function $f(x)=m x+b, f(-2)=11$ and $f(3)=-9 .$ Find $m$ and $b$.

AG
Ankit Gupta
Numerade Educator
02:14

Problem 52

For the linear function $f(x)=m x+b, f(-3)=23$ and $f(2)=-7 .$ Find $m$ and $b$.

AG
Ankit Gupta
Numerade Educator
02:25

Problem 53

Write the linear system whose solution set is {(6, 2)}. Express each equation in the system in slope-intercept form.

Mukesh Devi
Mukesh Devi
Numerade Educator
01:41

Problem 54

Write the linear system whose solution set is $\varnothing .$ Express each equation in the system in slope-intercept form.

AG
Ankit Gupta
Numerade Educator
00:42

Problem 55

How many radios must be produced and sold for the company to break even?

AG
Ankit Gupta
Numerade Educator
00:37

Problem 56

More than how many radios must be produced and sold for the company to have a profit?

AG
Ankit Gupta
Numerade Educator
01:50

Problem 57

Use the formulas shown in the voice balloons to find $R(200)-C(200) .$ Describe what this means for the company.

AG
Ankit Gupta
Numerade Educator
01:44

Problem 58

Use the formulas shown in the voice balloons to find $R(300)-C(300) .$ Describe what this means for the company.

AG
Ankit Gupta
Numerade Educator
01:46

Problem 59

a. Use the formulas shown in the voice balloons to write the company's profit function, $P,$ from producing and selling $x$ radios.
b. Find the company's profit if $10,000$ radios are produced and sold.

AG
Ankit Gupta
Numerade Educator
01:59

Problem 60

a. Use the formulas shown in the voice balloons to write the company's profit function, $P,$ from producing and selling $x$ radios.
b. Find the company's profit if $20,000$ radios are produced and sold.

AG
Ankit Gupta
Numerade Educator
02:38

Problem 61

A company that manufactures small canoes has a fixed cost of $\$ 18,000 .$ It costs $\$ 20$ to produce each canoe. The selling price is $\$ 80$ per canoe. (In solving this exercise, let $x$ represent the number of canoes produced and sold.)

AG
Ankit Gupta
Numerade Educator
02:59

Problem 62

A company that manufactures bicycles has a fixed cost of $\$ 100,000 .$ It costs $\$ 100$ to produce each bicycle. The selling price is $\$ 300$ per bike. (In solving this exercise, let $x$ represent the number of bicycles produced and sold.)

AG
Ankit Gupta
Numerade Educator
03:11

Problem 63

You invest in a new play. The cost includes an overhead of $\$ 30,000,$ plus production costs of $\$ 2500$ per performance. A sold-out performance brings in $\$ 3125 .$ (In solving this exercise, let $x$ represent the number of sold-out performances.

AG
Ankit Gupta
Numerade Educator
03:37

Problem 64

You invested $\$ 30,000$ and started a business writing greeting cards. Supplies cost 24 per card and you are selling each card for $50 \% .$ (In solving this exercise, let $x$ represent the number of cards produced and sold.)

AG
Ankit Gupta
Numerade Educator
03:07

Problem 65

The table shows the price of a gallon of unleaded premium gasoline. For each price, the table lists the number of gallons per day that a gas station sells and the number of gallons per day that can be supplied.

$$\begin{array}{lll}{\text { Price per }} & {\text { Gallons Demanded }} & {\text { Gallons Supplied }} \\ {\text { Gallon }} & {\text { per Day }} & {\text { per Day }} \\ {\$ 3.20} & {1400} & {200} \\ {\$ 3.60} & {1200} & {600} \\ {\$ 4.40} & {800} & {1400} \\ {\$ 4.80} & {600} & {1800}\end{array}$$

The data in the table are described by the following demand and supply models:
Demand Model $\quad$ Supply Model
$p=-0.002 x+6 \quad p=0.001 x+3$

a. Solve the system and find the equilibrium quantity and the equilibrium price for a gallon of unleaded premium gasoline.
b. Use your answer from part (a) to complete this statement: If unleaded premium gasoline is sold for _____ per gallon, there will be a demand for ______ gallons per day and ______ gallons will be supplied per day.

AG
Ankit Gupta
Numerade Educator
02:54

Problem 66

The table shows the price of a package of cookies. For each price, the table lists the number of packages that consumers are willing to buy and the number of packages that bakers are willing to supply.
a. Solve the system and find the equilibrium quantity and the equilibrium price for a package of cookies.
b. Use your answer from part (a) to complete this statement: If cookies are sold for _____ per package, there will be a demand for ______ million packages per week and bakers will supply ______ million packages per week.

AG
Ankit Gupta
Numerade Educator
04:16

Problem 67

The bar graph indicates that fewer U.S. adults are getting married.
The data can be modeled by the following system of linear equations:
$\left\{\begin{aligned}-3 x+10 y &=160 \\ x+2 y &=142 \end{aligned}\right.$
a. Use these models to determine the year, rounded to the nearest year, when the percentage of never-married adults will be the same as the percentage of married adults. For that year, approximately what percentage of Americans, rounded to the nearest percent, will belong to each group?
b. How is your approximate solution from part (a) shown by the following graphs?

AG
Ankit Gupta
Numerade Educator
03:25

Problem 68

The graph shows that from 2000 through 2006, Americans unplugged land lines and switched to cellphones.
a. Use the graphs to estimate the point of intersection. In what year was the number of cellphone and land-line customers the same? How many millions of customers were there for each?
b. The function $4.3 x+y=198$ models the number of land-line customers, in millions, $x$ years after 2000 . The function $y=19.8 x+98$ models the number of cellphone customers, in millions, $x$ years after $2000 .$ Use these models to determine the year, rounded to the nearest year, when the number of cellphone and land-line customers was the same. According to the models, how many millions of customers, rounded to the nearest ten million, were there for each?
c. How well do the models in part (b) describe the point of intersection of the graphs that you estimated in part (a)?

AG
Ankit Gupta
Numerade Educator
02:25

Problem 69

We opened this section with a study showing that late in the semester, procrastinating students reported more symptoms of physical illness than their nonprocrastinating peers.
a. At the beginning of the semester, procrastinators reported an average of 0.8 symptoms, increasing at a rate of 0.45 symptoms per week. Write a function that models the average number of symptoms after x weeks.
b. At the beginning of the semester, nonprocrastinators reported an average of 2.6 symptoms, increasing at a rate of 0.15 symptoms per week. Write a function that models the average number of symptoms after x weeks.
c. By which week in the semester did both groups report the same number of symptoms of physical illness? For that week, how many symptoms were reported by each group? How is this shown in Figure 8.1 on page 824?

AG
Ankit Gupta
Numerade Educator
03:32

Problem 70

Harsh, mandatory minimum sentences for drug offenses account for more than half the population in U.S. federal prisons. The bar graph shows the number of inmates in federal prisons, in thousands, for drug offenses and all other crimes in 1998 and 2010. (Other crimes include murder, robbery, fraud, burglary, weapons offenses, immigration offenses, racketeering, and perjury.)
a. In 1998, there were 60 thousand inmates in federal prisons for drug offenses. For the period shown by the graph, this number increased by approximately 2.8 thousand inmates per year. Write a function that models the number of inmates, y, in thousands, for drug offenses x years after 1998.
b. In 1998, there were 44 thousand inmates in federal prisons for all crimes other than drug offenses. For the period shown by the graph, this number increased by approximately 3.8 thousand inmates per year. Write a function that models the number of inmates, y, in thousands, for all crimes other than drug offenses x years after 1998.
c. Use the models from parts (a) and (b) to determine in which year the number of federal inmates for drug offenses was the same as the number of federal inmates for all other crimes. How many inmates were there for drug offenses and for all other crimes in that year?

AG
Ankit Gupta
Numerade Educator
04:43

Problem 71

The graphs show changing attitudes toward gay marriage for the period from 2001 through 2015.

a. Write the slope-intercept equation of the line that models the percentage of the U.S. public that supported gay marriage, y, x years after 2001. Round the value of the slope, m, to one decimal place. If necessary, round the value of the y-intercept to the nearest whole number.
b. Write the slope-intercept equation of the line that models the percentage of the U.S. public that opposed gay marriage, y, x years after 2001. Round the value of the slope, m, to one decimal place. If necessary, round the value of the y-intercept to the nearest whole number.
c. Use the models from parts (a) and (b) to determine the year, to the nearest whole year, during which the percentage who supported gay marriage was the same as the percentage who opposed gay marriage.

AG
Ankit Gupta
Numerade Educator
03:22

Problem 72

The graphs show per capita consumption of soda and bottled water in the United States, in gallons,from 2000 through 2015.

a. Write the slope-intercept equation of the line that models soda consumption per capita, y, in gallons, x years after 2000.
b. Write the slope-intercept equation of the line that models bottled water consumption per capita, y, in gallons, x years after 2000.
c. Use the models from parts (a) and (b) to determine the year, to the nearest whole year, during which per capita soda consumption was the same as per capita water consumption.

AG
Ankit Gupta
Numerade Educator
01:31

Problem 73

The current generation of college students grew up playing interactive online games, and many continue to play in college. The bar graph shows the percentage of U.S. college students playing online games, by gender.

A total of 41% of college men play online games multiple times per day or once per day. The difference in the percentage who play multiple times per day and once per day is 7%. Find the percentage of college men who play online games multiple times per day and the percentage of college men who play online games once per day.

AG
Ankit Gupta
Numerade Educator
01:32

Problem 74

A number of studies have emphasized the importance of sleep for students’ success in their academic performance. The bar graph shows the actual sleep hours and the sleep hours to function best for U.S. college students.

A total of 45% of college students sleep between 5 and 7 hours or between 9 and 11 hours. The difference in the percentage who sleep between 5 and 7 hours and between 9 and 11 hours is 41%. Find the percentage of college students who sleep between 5 and 7 hours and the percentage of college students who sleep between 9 and 11 hours.

AG
Ankit Gupta
Numerade Educator
02:54

Problem 75

How many ounces of a 15% alcohol solution must be mixed with 4 ounces of a 20% alcohol solution to make a 17% alcohol solution?

AG
Ankit Gupta
Numerade Educator
02:58

Problem 76

How many ounces of a 50% alcohol solution must be mixed with 80 ounces of a 20% alcohol solution to make a 40% alcohol solution?

AG
Ankit Gupta
Numerade Educator
06:13

Problem 77

At the north campus of a performing arts school, 10% of the students are music majors. At the south campus, 90% of the students are music majors. The campuses are merged into one east campus. If 42% of the 1000 students at the east campus are music majors, how many students did each of the north and south campuses have before the merger?

AG
Ankit Gupta
Numerade Educator
05:39

Problem 78

At the north campus of a small liberal arts college, 10% of the students are women. At the south campus, 50% of the students are women. The campuses are merged into one east campus. If 40% of the 1200 students at the east campus are women, how many students did each of the north and south campuses have before the merger?

AG
Ankit Gupta
Numerade Educator
03:27

Problem 79

A hotel has 200 rooms. Those with kitchen facilities rent for $\$ 100$ per night and those without kitchen facilities rent for $\$ 80$ per night. On a night when the hotel was completely occupied, revenues were $\$ 17,000 .$ How many of each type of room does the hotel have?

AG
Ankit Gupta
Numerade Educator
02:35

Problem 80

A new restaurant is to contain two-seat tables and four-seat tables. Fire codes limit the restaurant's maximum occupancy to 56 customers. If the owners have hired enough servers to handle 17 tables of customers, how many of each kind of table should they purchase?

AG
Ankit Gupta
Numerade Educator
02:46

Problem 81

When a crew rows with the current, it travels 16 miles in 2 hours. Against the current, the crew rows 8 miles in 2 hours. Let $x=$ the crew's rowing rate in still water and let $y=$ the rate of the current. The following chart summarizes this information:

AG
Ankit Gupta
Numerade Educator
02:45

Problem 82

When an airplane flies with the wind, it travels 800 miles in 4 hours. Against the wind, it takes 5 hours to cover the same distance. Find the plane’s rate in still air and the rate of the wind.

AG
Ankit Gupta
Numerade Educator
02:37

Problem 83

An isosceles triangle containing two angles with equal measure is shown. The degree measure of each triangle’s three interior angles and an exterior angle is represented with variables. Find the measure of the three interior angles.

AG
Ankit Gupta
Numerade Educator
02:41

Problem 84

An isosceles triangle containing two angles with equal measure is shown. The degree measure of each triangle’s three interior angles and an exterior angle is represented with variables. Find the measure of the three interior angles.

AG
Ankit Gupta
Numerade Educator
01:11

Problem 85

What is a system of linear equations? Provide an example with your description.

AG
Ankit Gupta
Numerade Educator
02:26

Problem 86

What is the solution of a system of linear equations?

AG
Ankit Gupta
Numerade Educator
02:31

Problem 87

Explain how to solve a system of equations using the substitution method. Use $y=3-3 x$ and $3 x+4 y=6$ to illustrate your explanation.

AG
Ankit Gupta
Numerade Educator
02:57

Problem 88

Explain how to solve a system of equations using the addition method. Use $3 x+5 y=-2$ and $2 x+3 y=0$ to illustrate your explanation.

AG
Ankit Gupta
Numerade Educator
01:59

Problem 89

When is it easier to use the addition method rather than the substitution method to solve a system of equations?

AG
Ankit Gupta
Numerade Educator
02:41

Problem 90

When using the addition or substitution method, how can you tell if a system of linear equations has infinitely many solutions? What is the relationship between the graphs of the two equations?

AG
Ankit Gupta
Numerade Educator
02:12

Problem 91

When using the addition or substitution method, how can you tell if a system of linear equations has no solution? What is the relationship between the graphs of the two equations?

AG
Ankit Gupta
Numerade Educator
02:36

Problem 92

Describe the break-even point for a business.

AG
Ankit Gupta
Numerade Educator
04:06

Problem 93

Verify your solutions to any five exercises in Exercises $5-42$ by using a graphing utility to graph the two equations in the system in the same viewing rectangle. Then use the intersection feature to display the solution.

AG
Ankit Gupta
Numerade Educator
01:27

Problem 94

Determine whether each statement makes sense or does not make sense, and explain your reasoning.
Even if a linear system has a solution set involving fractions, such as $\left\{\left(\frac{8}{11}, \frac{43}{11}\right)\right\},$ I can use graphs to determine if the solution set is reasonable.

AG
Ankit Gupta
Numerade Educator
01:22

Problem 95

Each equation in a system of linear equations has infinitely many ordered-pair solutions.

AG
Ankit Gupta
Numerade Educator
01:41

Problem 96

Every linear system has infinitely many ordered-pair solutions.

AG
Ankit Gupta
Numerade Educator
01:51

Problem 97

If I know the perimeter of this rectangle and triangle, each in the same unit of measure, I can use a system of linear equations to determine values for x and y.

AG
Ankit Gupta
Numerade Educator
02:59

Problem 98

Write a system of equations having {(-2, 7)} as a solution set. (More than one system is possible.)

AG
Ankit Gupta
Numerade Educator
03:28

Problem 99

Solve the system for $x$ and $y$ in terms of $a_{1}, b_{1}, c_{1}, a_{2}, b_{2},$ and $c_{2}$
$$\left\{\begin{array}{l}
{a_{1} x+b_{1} y=c_{1}} \\
{a_{2} x+b_{2} y=c_{2}}
\end{array}\right.$$

AG
Ankit Gupta
Numerade Educator
02:11

Problem 100

Two identical twins can only be distinguished by the characteristic that one always tells the truth and the other always lies. One twin tells you of a lucky number pair: “When I multiply my first lucky number by 3 and my second lucky number by 6, the addition of the resulting numbers produces a sum of 12. When I add my first lucky number and twice my second lucky number, the sum is 5.” Which twin is talking?

AG
Ankit Gupta
Numerade Educator
07:31

Problem 101

A marching band has 52 members, and there are 24 in the pom-pom squad. They wish to form several hexagons and squares like those diagrammed below. Can it be done with no people left over?

Derek Follett
Derek Follett
Numerade Educator
01:46

Problem 102

The group should write four different word problems that can be solved using a system of linear equations in two variables. All of the problems should be on different topics. The group should turn in the four problems and their algebraic solutions.

AG
Ankit Gupta
Numerade Educator
01:05

Problem 103

Find the domain of each function.
$f(x)=\ln (6-x) \quad \text { (Section } 4.2, \text { Example } 10)$

AG
Ankit Gupta
Numerade Educator
01:33

Problem 104

$g(x)=\frac{x-6}{x^{2}-36}$
(Section 3.5, Example 1)

AG
Ankit Gupta
Numerade Educator
02:53

Problem 105

Find the domain of each function.
Solve: $\quad \log _{3} x+\log _{3}(x+6)=3$
(Section 4.4,Example 7)

AG
Ankit Gupta
Numerade Educator
03:05

Problem 106

Determine the amplitude, period, and phase shift of $y=-2 \cos \left(2 x-\frac{\pi}{2}\right) .$ Then graph one period of the function. (Section 5.5, Example 6)

AG
Ankit Gupta
Numerade Educator
01:45

Problem 107

If $x=3, y=2,$ and $z=-3,$ does the ordered triple $(x, y, z)$ satisfy the equation $2 x-y+4 z=-8 ?$

AG
Ankit Gupta
Numerade Educator
01:32

Problem 108

Consider the following equations:
$\left\{\begin{array}{l}{5 x-2 y-4 z=3} \\ {3 x+3 y+2 z=-3}\end{array}\right.$
Eliminate $z$ by copying Equation $1,$ multiplying Equation 2 by $2,$ and then adding the equations.

AG
Ankit Gupta
Numerade Educator
01:15

Problem 109

Write an equation involving $a, b,$ and $c$ based on the following description:
When the value of $x$ in $y=a x^{2}+b x+c$ is $4,$ the value of $y$ is 1682

AG
Ankit Gupta
Numerade Educator