Answer:
x = 80
Explanation:
The whole reason algebra exists is to solve for a variable. Therefore, the only way to get x by itself or to see what x equals is to subtract 20 from both sides. Doing this will make x be all alone on one side of the equation and to see what x is.
x + 20 = 100
x + 20 -20 = 100 -20
x = 80