The perimeter of a rectangle that is 70 can be put into an equation like this: 2l + 2w = 70
The information given for us is this: length = x width = x - 9
Plug in the values for length and width: 2(x) + 2(x - 9) = 70 Multiply through the parenthesis: 2x + 2x - 18 = 70 Combine like terms: 4x = 88 Divide by 4 on both sides: x = 22
