Answer
One common solution $\Rightarrow$ $(7,-5)$
Work Step by Step
We use the addition method below:
We add the 2 equations:
$x+2y=-3$
$2x+y=9$
Multiply both sides of the 1st equation by $-2$ to cancel $x$.
$-2x-4y=6$
$\underline{+2x+y=9}$
$-3y=15$
Solve for $y$:
$y=\frac{15}{-3}=-5$
Substitute into any of the 2 equations and solve for $x$:
$x+2y=-3$
$x+2(-5)=-3$
$x-10=-3$
$x=10-3$
$x=7$
