The perimeter of a backyard is 375 feet

Question

The perimeter of a backyard is 375 feet. If the width is 15 feet less than the length, find the length of the yard.

Answer 1

Let l = the length

Let l - 15 = the width

P = 2l + 2w

375 = 2l + 2(l - 15)

375 = 2l + 2l - 30

405 = 4l

101 1/4 feet = l