Question

A building in a city has a rectangular base. The length of the base measures 75 ft less than three times the width. The perimeter of this base is 810ft. What are the dimensions of the base?

Answer 1

The perimeter of a rectangle is:
2L +2W = P
W = x
L = 3x - 75

2(x) + 2(3x - 75) = 810

2x + 6x - 150 = 810
8x = 960
x = 120; W = 120 ft. L = 285 ft

Answer 2

P = 2l +2w
820 = 2(w - 70) + 2w
820 = 4w - 140  
820 - 140 = 4w
680/4 = w
170 = w
let me know if you need an explanation of how i got any of the steps
:)