L=33 and W=7
Step one, What do we know?
We are told that the perimeter is 80 feet; since the perimeter of a rectangle is 2 times the length plus the width. We are also told that the length is 5 feet longer than four times the width.
Step two, Start solving it.
Combining these two we have 4w + 5=40 - w. We put the w on the right side and the 5 on the left side by adding and subtracting. Now we have 5w=35. We divide both sides by 5 and we get W=7. In order to figure out L, we do
40 - W. We get L=33.