Question

-8x+4y=28 solve for y

Answer 1

This is how I would do it:
-8x=28-4y divide the entire equation by 4
-2x=7-y Put y back on the left and put x on the right 
y=7-2x.

Answer 2

-8x+4y=28 You need to subtract -8x from both sides leaving:
4y=8x+28 From here you need to divide by 4 on both sides leaving:
y= 8x+28/4 Simplify:
y=2x+7