Question
If $(a, b)$ is a solution of the system of equations $\left\{\begin{array}{c}{2 x-y=7} \\ {x+y=8}\end{array}\right.$, then the difference, $a-b,$ equals(A) $-12$(B) $-10$(C) 0(D) 2(E) 4
Step 1
Step 1: We are given the system of equations: \[\begin{cases} 2x - y = 7 \\ x + y = 8 \end{cases}\] We are told that $(a, b)$ is a solution to this system, so we can rewrite the system as: \[\begin{cases} 2a - b = 7 \\ a + b = 8 \end{cases}\] Show more…
Show all steps
Your feedback will help us improve your experience
Dilip Paruchuri and 85 other educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Find constants $a$ and $b$ so that $(8,-7)$ is the solution of the system $$ \left\{\begin{array}{l} a x+b y=10 \\ b x+a y=-5 \end{array}\right. $$
Systems of Equations
Systems of Two Linear Equations in Two Unknowns
Find constants $a$ and $b$ so that (8,-7) is the solution of the system $$\left\{\begin{array}{l}a x+b y=10 \\b x+a y=-5\end{array}\right.$$
If $x^{2}+x y+y^{2}=\frac{7}{4}$, then $\frac{d y}{d x}$ at $x=1$ and $y=\frac{1}{2}$ is (a) $\frac{3}{4}$ (b) $\frac{-5}{4}$ (c) $\frac{21}{8}$ (d) $\frac{-21}{8}$
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD