Question

If 3x−y=12, what is the value of
8x
2y

Answer 1

`8x=32\\2y=-24`

Explanation:

When solving for 1 variable, set the other to 0 and solve.

`3x-y(0)=12\\3x=12\\x=4\\4*8=32\\8x=32\\\\3(0)-y=12\\-y=12\\y=-12\\-12*2=-24\\2y=-24`