solving systems of equations: 1.) 2x + 9y = -13 2x - 3y = 23?

2x + 9y = -13
2x - 3y = 23
12y = -36
y = -3
x = 7

Subtract one equation from the other, which will eliminate the x terms.
Solve the resulting equation for y.
Then use y to solve for x.

2x + 9y = -13
-[2x - 3y = 23]
---------------------
........12y = -36
........y = -3 answer//

solving for y from eq1


2x + 9y = -13
2x + 9(-3) = - 13
2x - 27 = - 13
2x = - 13 + 27
2x = 14
x = 7 answer//

2x + 9y = -13,
2x - 3y = 23
12y = -36
y = -3
x = 7