Addition Property of Equality

When rewriting equations it's important to make the the same operation on both sides to ensure that the equality still holds. So, if a number is added to one side, the same number must be added to the other side. In the equation 4x-7=5, 7 can be added to both sides. 4x-7 + 7=5 + 7 ⇔ 4x = 12