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Essentials of Precalculus

Richard N. Aufmann, Richard D. Nation

Chapter 1

Functions and Graphs - all with Video Answers

Educators


Section 1

Equations and Inequalities

01:09

Problem 1

Solve and check each equation.
$$1.2 x+10=40$$

Julie Silva
Julie Silva
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01:11

Problem 2

Solve and check each equation.
$$-3 y+20=2$$

Julie Silva
Julie Silva
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01:12

Problem 3

Solve and check each equation.
$$5 x+2=2 x-10$$

Julie Silva
Julie Silva
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01:09

Problem 4

Solve and check each equation.
$$4 x-11=7 x+20$$

Julie Silva
Julie Silva
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01:19

Problem 5

Solve and check each equation.
$$2(x-3)-5=4(x-5)$$

Julie Silva
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01:09

Problem 6

Solve and check each equation.
$$6(5 s-11)-12(2 s+5)-0$$

Julie Silva
Julie Silva
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01:07

Problem 7

Solve and check each equation.
$$\frac{3}{4} x+\frac{1}{2}=\frac{2}{3}$$

Julie Silva
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01:05

Problem 8

Solve and check each equation.
$$\text { 8. } \frac{x}{4}-5=\frac{1}{2}$$

Julie Silva
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01:10

Problem 9

Solve and check each equation.
$$\frac{2}{3} x-5=\frac{1}{2} x-3$$

Julie Silva
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01:13

Problem 10

Solve and check each equation.
$$\frac{1}{2} x+7-\frac{1}{4} x=\frac{19}{2}$$

Julie Silva
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01:05

Problem 11

Solve and check each equation.
$$0.2 x+0.4=3.6$$

Julie Silva
Julie Silva
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01:09

Problem 12

Solve and check each equation.
$$0.04 x-0.2=0.07$$

Julie Silva
Julie Silva
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02:01

Problem 13

Solve and check each equation.
$$\frac{3}{5}(n+5)-\frac{3}{4}(n-11)=0$$

Julie Silva
Julie Silva
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01:59

Problem 14

Solve and check each equation.
$$-\frac{5}{7}(p+11)+\frac{2}{5}(2 p-5)=0$$

Julie Silva
Julie Silva
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02:09

Problem 15

Solve and check each equation.
$$3(x+5)(x-1)-(3 x+4)(x-2)$$

Julie Silva
Julie Silva
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01:51

Problem 16

Solve and check each equation.
$$5(x+4)(x-4)=(x-3)(5 x+4)$$

Julie Silva
Julie Silva
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01:14

Problem 17

Solve and check each equation.
$$5(x+4)(x-4)=(x-3)(5 x+4)$$

Julie Silva
Julie Silva
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01:17

Problem 17

Solve and check each equation.
$$0.08 x+0.12(4000-x)=432$$

Julie Silva
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01:24

Problem 18

Solve and check each equation.
$$0.075 y+0.06(10,000-y)-727.50$$

Julie Silva
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01:15

Problem 19

solve each quadratic equation by factoring and applying the zero product property.
$$x^{2}-2 x-15=0$$

Julie Silva
Julie Silva
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01:17

Problem 20

solve each quadratic equation by factoring and applying the zero product property.
$$y^{2}+3 y-10=0$$

Julie Silva
Julie Silva
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02:10

Problem 21

solve each quadratic equation by factoring and applying the zero product property.
$$8 y^{2}+189 y-72=0$$

Julie Silva
Julie Silva
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02:19

Problem 22

solve each quadratic equation by factoring and applying the zero product property.
$$12 w^{2}-41 w+24=0$$

Julie Silva
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01:09

Problem 23

solve each quadratic equation by factoring and applying the zero product property.
$$3 x^{2}-7 x-0$$

Julie Silva
Julie Silva
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01:09

Problem 24

solve each quadratic equation by factoring and applying the zero product property.
$$5 x^{2}=-8 x$$

Julie Silva
Julie Silva
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01:44

Problem 25

solve each quadratic equation by factoring and applying the zero product property.
$$(x-5)^{2}-9=0$$

Julie Silva
Julie Silva
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01:57

Problem 26

solve each quadratic equation by factoring and applying the zero product property.
$$(3 x+4)^{2}-16=0$$

Julie Silva
Julie Silva
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01:50

Problem 27

Solve by completing the square or by using the quadratic formula.
$$x^{2}-2 x-15=0$$

Julie Silva
Julie Silva
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01:46

Problem 28

Solve by completing the square or by using the quadratic formula.
$$x^{2}-5 x-24=0$$

Julie Silva
Julie Silva
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01:19

Problem 29

Solve by completing the square or by using the quadratic formula.
$$x^{2}+x-1=0$$

Julie Silva
Julie Silva
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01:42

Problem 30

Solve by completing the square or by using the quadratic formula.
$$x^{2}+x-2=0$$

Julie Silva
Julie Silva
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01:49

Problem 31

Solve by completing the square or by using the quadratic formula.
$$2 x^{2}+4 x+1=0$$

Julie Silva
Julie Silva
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01:59

Problem 32

Solve by completing the square or by using the quadratic formula.
$$2 x^{2}+4 x-1=0$$

Julie Silva
Julie Silva
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01:27

Problem 33

Solve by completing the square or by using the quadratic formula.
$$3 x^{2}-5 x-3=0$$

Julie Silva
Julie Silva
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01:25

Problem 34

solve by completing the square or by using the quadratic formula.
$$3 x^{2}-5 x-4=0$$

Julie Silva
Julie Silva
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01:55

Problem 35

solve by completing the square or by using the quadratic formula.
$$\frac{1}{2} x^{2}+\frac{3}{4} x-1=0$$

Julie Silva
Julie Silva
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02:46

Problem 36

Solve by completing the square or by using the quadratic formula.
$$\frac{2}{3} x^{2}-5 x+\frac{1}{2}=0$$

Julie Silva
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02:31

Problem 37

Solve by completing the square or by using the quadratic formula.
$$\sqrt{2} x^{2}+3 x+\sqrt{2}-0$$

Julie Silva
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01:32

Problem 38

Solve by completing the square or by using the quadratic formula.
$$2 x^{2}+\sqrt{5} x-3=0$$

Julie Silva
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01:48

Problem 39

Solve by completing the square or by using the quadratic formula.
$$x^{2}-3 x+5$$

Julie Silva
Julie Silva
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01:49

Problem 40

Solve by completing the square or by using the quadratic formula.
$$-x^{2}-7 x-1$$

Julie Silva
Julie Silva
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01:11

Problem 41

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$2 x+3<11$$

Julie Silva
Julie Silva
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01:10

Problem 42

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$3 x-5>16$$

Julie Silva
Julie Silva
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01:20

Problem 43

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$x+4>3 x+16$$

Julie Silva
Julie Silva
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01:16

Problem 44

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$5 x+6<2 x+1$$

Julie Silva
Julie Silva
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01:15

Problem 45

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$-6 x+1 \geq 19$$

Julie Silva
Julie Silva
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01:17

Problem 46

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$-5 x+2 \leq 37$$

Julie Silva
Julie Silva
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01:44

Problem 47

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$-3(x+2) \leq 5 x+7$$

Julie Silva
Julie Silva
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01:41

Problem 48

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$-4(x-5)=2 x+15$$

Julie Silva
Julie Silva
Numerade Educator
01:52

Problem 49

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$-4(3 x-5)>2(x-4)$$

Julie Silva
Julie Silva
Numerade Educator
01:52

Problem 50

Use the properties of inequalities to solve each inequality. Write answers using interval notation.
$$3(x+7) \leq 5(2 x-8)$$

Julie Silva
Julie Silva
Numerade Educator
01:58

Problem 51

Solve each quadratic inequality. Use interval notation to write each solution set.
$$x^{2}+7 x>0$$

Julie Silva
Julie Silva
Numerade Educator
01:50

Problem 52

Solve each quadratic inequality. Use interval notation to write each solution set.
$$x^{2}-5 x \leq 0$$

Julie Silva
Julie Silva
Numerade Educator
02:12

Problem 53

Solve each quadratic inequality. Use interval notation to write each solution set.
$$x^{2}+7 x+10<0$$

Julie Silva
Julie Silva
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02:10

Problem 54

Solve each quadratic inequality. Use interval notation to write each solution set.
$$x^{2}+5 x+6<0$$

Julie Silva
Julie Silva
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02:37

Problem 55

Solve each quadratic inequality. Use interval notation to write each solution set.
$$x^{2}-3 x \geq 28$$

Julie Silva
Julie Silva
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02:25

Problem 56

Solve each quadratic inequality. Use interval notation to write each solution set.
$$x^{2}<-x+30$$

Julie Silva
Julie Silva
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03:39

Problem 57

Solve each quadratic inequality. Use interval notation to write each solution set.
$$6 x^{2}-4 \leq 5 x$$

Julie Silva
Julie Silva
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04:05

Problem 58

Solve each quadratic inequality. Use interval notation to write each solution set.
$$12 x^{2}+8 x=15$$

Julie Silva
Julie Silva
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01:01

Problem 59

Use interval notation to express the solution set of each inequality.
$$|x|<4$$

Julie Silva
Julie Silva
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01:17

Problem 60

Use interval notation to express the solution set of each inequality.
$$|x|>2$$

Julie Silva
Julie Silva
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01:11

Problem 61

Use interval notation to express the solution set of each inequality.
$$|x-1|<9$$

Julie Silva
Julie Silva
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01:17

Problem 62

Use interval notation to express the solution set of each inequality.
$$|x-3|<10$$

Julie Silva
Julie Silva
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01:34

Problem 63

Use interval notation to express the solution set of each inequality.
$$|x+3|>30$$

Julie Silva
Julie Silva
Numerade Educator
01:18

Problem 64

Use interval notation to express the solution set of each inequality.
$$|x+4|<2$$

Julie Silva
Julie Silva
Numerade Educator
01:42

Problem 65

Use interval notation to express the solution set of each inequality.
$$|2 x-1|>4$$

Julie Silva
Julie Silva
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01:22

Problem 66

Use interval notation to express the solution set of each inequality.
$$|2 x-9|<7$$

Julie Silva
Julie Silva
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01:23

Problem 67

Use interval notation to express the solution set of each inequality.
$$|x+3| \geq 5$$

Julie Silva
Julie Silva
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01:21

Problem 68

Use interval notation to express the solution set of each inequality.
$$|x-10| \geq 2$$

Julie Silva
Julie Silva
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01:28

Problem 69

Use interval notation to express the solution set of each inequality.
$$|3 x-10| \leq 14$$

Julie Silva
Julie Silva
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01:35

Problem 70

Use interval notation to express the solution set of each inequality.
$$|2 x-5| \geq 1$$

Julie Silva
Julie Silva
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01:59

Problem 71

Use interval notation to express the solution set of each inequality.
$$|4-5 x| \geq 24$$

Julie Silva
Julie Silva
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01:30

Problem 72

Use interval notation to express the solution set of each inequality.
$$|3-2 x| \leq 5$$

Julie Silva
Julie Silva
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01:09

Problem 73

Use interval notation to express the solution set of each inequality.
$$|x-5| \geq 0$$

Julie Silva
Julie Silva
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01:06

Problem 74

Use interval notation to express the solution set of each inequality.
$$|x-7| \geq 0$$

Julie Silva
Julie Silva
Numerade Educator
01:07

Problem 75

Use interval notation to express the solution set of each inequality.
$$|x-4| \leq 0$$

Julie Silva
Julie Silva
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01:09

Problem 76

Use interval notation to express the solution set of each inequality.
$$|2 x+7| \leq 0$$

Julie Silva
Julie Silva
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05:42

Problem 77

The perimeter of a rectangle is 27 centimeters, and its area is 35 square centimeters. Find the length and the width of the rectangle.

Julie Silva
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03:30

Problem 78

The perimeter of a rectangle is 34 feet and its area is 60 square feet. Find the length and the width of the rectangle.

Julie Silva
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04:17

Problem 79

A gardener wishes to use 600 feet of fencing to enclose a rectangular region and subdivide the region into two smaller rectangles. The total enclosed area is 15,000 square feet. Find the dimensions of the enclosed region.

Julie Silva
Julie Silva
Numerade Educator
04:51

Problem 80

A farmer wishes to use 400 yards of fencing to enclose a rectangular region and subdivide the region into three smaller rectangles. If the total enclosed area is 4800 square yards, find the dimensions of the enclosed region.
(Figure cant copy)

Julie Silva
Julie Silva
Numerade Educator
02:20

Problem 81

A bank offers two checking account plans. The monthly fee and charge per check for each plan are shown below. Under what conditions is it less expensive to use the Low Charge plan?
(Table cant copy)

Julie Silva
Julie Silva
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02:24

Problem 82

You can rent a car for the day from company A for $\$ 29.00$ plus $\$ 0.12$ a mile. Company B charges $\$ 22.00$ plus $\$ 0.21$ a mile. Find the number of miles $m$ (to the nearest mile) per day for which it is cheaper to rent from company A.

Julie Silva
Julie Silva
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01:58

Problem 83

A sales clerk has a choice between two payment plans. Plan A pays $\$ 100.00$ a week plus $\$ 8.00$ a sale. Plan B pays $\$ 250.00$ a week plus $\$ 3.50$ a sale. How many sales per week must be made for plan A to yield the greater paycheck?

Julie Silva
Julie Silva
Numerade Educator
01:49

Problem 84

A video store offers two rental plans. The yearly membership fee and the daily charge per video are shown below. How many videos can be rented per year if the No-fee plan is to be the less expensive of the plans?
(Table cant copy)

Julie Silva
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01:28

Problem 85

The average daily minimum-tomaximum temperatures for the city of Palm Springs during the month of September are $68^{\circ} \mathrm{F}$ to $104^{\circ} \mathrm{F}$. What is the corresponding temperature range measured on the Celsius temperature scale?

Julie Silva
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Numerade Educator
04:39

Problem 86

The ancient Greeks defined a rectangle as a “golden rectangle” if its length l and its width w satisfied the equation
$$\frac{1}{u v}=\frac{u}{l-u v}$$
a. Solve this formula for w.
b. If the length of a golden rectangle is 101 feet, determine its width. Round to the nearest hundredth.

Julie Silva
Julie Silva
Numerade Educator
02:16

Problem 87

The sum $S$ of the first $n$ natural numbers $1,2,3, \ldots, n$ is given by the formula
$$S=\frac{n}{2}(n+1)$$
How many consecutive natural numbers starting with 1 produce a sum of 253?

Julie Silva
Julie Silva
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03:36

Problem 88

The number of diagonals $D$ of a polygon with $n$ sides is given by the formula
$$D=\frac{n}{2}(n-3)$$
a. Determine the number of sides of a polygon with 464 diagonals.
b. Can a polygon have 12 diagonals? Explain.

Julie Silva
Julie Silva
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02:35

Problem 89

The monthly revenue $R$ for a product is given by $R-420 x-2 x^{2},$ where $x$ is the price in dollars of each unit produced. Find the interval in terms of $x$ for which the monthly revenue is greater than zero.

Julie Silva
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01:27

Problem 90

Write an absolute value inequality to represent all real numbers within
a. 8 units of 3
b. $k$ units of $j$ (assume $k>0$ )

Julie Silva
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03:42

Problem 91

The equation
$$s=-16 t^{2}+v_{0} t+s_{0}$$
gives the height $s$, in feet above ground level, of an object t seconds after the object is thrown directly upward from a height $s_{0}$ feet above the ground with an initial velocity of $v_{0}$ feet per second. A ball is thrown directly upward from ground level with an initial velocity of 64 feet per second. Find the time interval during which the ball has a height of more than 48 feet.

Julie Silva
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03:14

Problem 92

A ball is thrown directly upward from a height of 32 feet above the ground with an initial velocity of 80 feet per second. Find the time interval during which the ball will be more than 96 feet above the ground. (Hint: See Exercise 91.)
(Figure cant copy)

Julie Silva
Julie Silva
Numerade Educator
02:01

Problem 93

The length of the side of a square has been measured accurately to within 0.01 foot. This measured length is 4.25 feet.
a. Write an absolute value inequality that describes the relationship between the actual length of each side of the square s and its measured length.
b. Solve the absolute value inequality you found in part a. for s.

Julie Silva
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01:05

Problem 94

Evaluate $\frac{x_{1}+x_{2}}{2}$ when $x_{1}=4$ and $x_{2}=-7.$

Julie Silva
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01:07

Problem 95

Simplify $\sqrt{50} .[\mathrm{A} .1]$

Julie Silva
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01:03

Problem 96

Is $y=3 x-2$ a true equation when $y-5$ and $x=-1 ?$ [1.1]

Julie Silva
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01:13

Problem 97

If $y=x^{2}-3 x+2,$ find $x$ when $y=0 .[1.1]$

Julie Silva
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01:07

Problem 98

Evaluate $|-x-y|$ when $x-3$ and $y=-1 .[1.1]$

Julie Silva
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01:04

Problem 99

Evaluate $\sqrt{a^{2}+b^{2}}$ when $a=-3$ and $b=4 .[\text { A. } 1]$

Julie Silva
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