Here's a trick.
Don't solve all the equations, you're given the answer to x so just substitute.
5/2*8+7/2=3/4*8+14
23.5=20 INCORRECT
5/4*8-9=3/2*8-21
1=-9 INCORRECT
5/4*8-2=3/2*8-4 <- YOUR ANSWER
8=8 CORRECT
