Solve the system of equations by the addition method.
-$\left\{ \begin{array} { r r }
7 x + 2 y = & 9 \
- 2 x - 2 y = & - 24
\end{array} \right.$
A)(2, -15)
B)(-3, 15)
C)(7, -15)
D)infinite number of solutions

Question

Solve the system of equations by the addition method.
-$\left\{ \begin{array} { r r } 
7 x + 2 y = & 9 \
- 2 x - 2 y = & - 24
\end{array} \right.$
A)(2, -15)
B)(-3, 15)
C)(7, -15)
D)infinite number of solutions

Quizplus · Accepted Answer

By adding the two equations, the $2y$ terms cancel out, resulting in $5x = -15$, which gives $x = -3$. Substituting $x = -3$ into the first equation, we find $y = 15$.

Solve the System of Equations by the Addition Method {7x+2y=9−2x−2y=−24\left\{ \begin{array} { r r } 7 x + 2 y = & 9 \\- 2 x - 2 y = & - 24\end{array} \right.{7x+2y=−2x−2y=​9−24​

Solve the System of Equations by the Addition Method $\left\{ \begin{array} { r r } 7 x + 2 y = & 9 \\- 2 x - 2 y = & - 24\end{array} \right.$