# The perimeter of a rectangle is 40. The width is four less than 5 times the length. How do you find the dimensions of the rectangle?

Sep 23, 2015

I found $16 \mathmr{and} 4$

#### Explanation:

The perimeter $P$ is the sum of the 4 lengths:
$P = 40 = W + W + L + L = 2 W + 2 L$
$40 = 2 \left(5 L - 4\right) + 2 L$
$40 = 10 L - 8 + 2 L$
$L = \frac{48}{12} = 4$
So: $W = 5 \cdot 4 - 4 = 16$