4x = 8
First, you want to divide both sides by 4. So:
4x/4 = 8/4
If you don't get why, it's kind of like 1 = 1. You divide both sides so that the equation is still equal. 1 divided by 1 is equal to 1 divided by 1.
So, 4x/4 is x, and 8/4 is 2. So, x = 2.