Answer :

luana
[tex]7x-xy=-18\ \ \ \ and\ \ \ \ \ x=-4\\\\7\cdot(-4)-(-4)y=-18\\-28+4y=-18\\4y=-18+28\\4y=8\ \ \ \ \ \ \ |:4\\y=2[/tex]
7x - xy = -18     x = -4
 
First, fill the -4 in where the "x's" are.

7(-4) - (-4)y = -18

Then, add the 28 over.

-28 + 4y = -18
+28           +28

4y = 10

Then, get the variable by itself, so you would divide the 4 over.

4y = 10
÷4    ÷4

y = 2.5