3x+7y=−17

−3x+9y=−15

First, solve the first equation for x:

3x = -17 - 7y
x = (-17 - 7y)/3

Substitute the expression for x into the second equation:

-3((-17 - 7y)/3) + 9y = -15
-17 - 7y + 9y = -15
-17 + 2y = -15
2y = 2
y = 1

Substitute the value of y back into the first equation to solve for x:

3x + 7(1) = -17
3x + 7 = -17
3x = -24
x = -8

The solution to the system of equations is x = -8 and y = 1.