In order to find a solution to an algebraic equation such as this one we simply need to isolate the variable. We do this by applying the opposite operation to each side in order to get rid of the other factors and get the variable alone. Like so...
20 = y + 12 ... we need to subtract 12 from both sides to get rid of the 12 on the right side with the variable y.
20 - 12 = y + 12 - 12
8 = y
Finally, we can see that the value of the variable y is 8
