dont get how to solve this can someone help

Question

the perimeter of a rectangular park is 21,705.3inches. the length of the park is 9,830.2inches longer than the width. what is the length of the park?

Answer 1

Let length L and width W.

W=L-9830.2

perimeter = 21705.3= 2(L+W)

 21705.3=2(L+L-9830.2)

 21705.3= 4L-19660.4

4L=21705.3+19660.4=41365.7

L=41365.7/4

L=10341.4 in

W=10341.4-9830.2=511.2 in

Check:  21705.3=2(10341.4+511.2)