I don't know how to start solving this

Question

Franco has a total of 200 feet of fencing. He wants to use all of the fencing to create a small rectangular garden. The garden will be 4 times as long as it is wide. Find the length and the width of the final garden.

Answer 1

Let L = length and  W = width

2(L + W) = 200

L= 4W

 

Substitute:

2(4W + W) = 200

 

10W = 200

W = 20

L = 80