Question

Solve by elimination:
-9x-4y=-20
5x+4y=4

Answer 1

Eliminate the y by making them zero.

-9x=-20
5x=4

Combine

-4x=-16

Divide each side by 4 to put the x alone

-4x/4= -16/-4

X=4

Plug x=4 back into one of the equations. It does not matter

5(4)+4y=4

20+4y=4
-20 -20

4y=-16
Divide by 4

Y=-4