Math about one-step equation

Question

The width of a rectangular yard is 4 feet less than the length. The perimeter is 28 feet. What is the area of the yard?

Answer 1

length = L

width =W=L-4

 

2(L+W) = Perimete

 

2(L+L-4) = 28

 

2(2L-4)=28

4L -8 =28

4L =36

L=9

W=9-4=5

 

Area = L* W =9*5=45 square yard