Dimensions of a Rectangle

Find the dimensions of a rectangle whose length is 40 inches more than its width and whose perimeter is 300 in?

x = width
x + 40 = length {length is 40 more than width}

x + x + x + 40 + x + 40 = 300 {got perimeter by adding all sides}
4x + 80 = 300 {combined like terms}
4x = 220 {subtracted 80 from both sides}
x = 55 inches {width}
x + 40 = 95 inches (length)

- Algebra House