use a matrix to find the solution to the system of equations -8x-8y=-16 6x-9y=-108

We want to use a matrix to solve
-8x - 8y = -16
6x - 9y = -108

Before solving, simplify the equations as follows:
Divide the first equation by -8 to obtain
x + y = 2             (1)
Divide the second equation by 3 to obtain
2x - 3y = -36       (2)

In matrix form, the equations are


The determinant of the matrix is
D = (1)(-3) - (1)(2) = -5

Use Cramer's Rule.

Similalrly, 


  (-6, 8)  or x = -6, y = 8