Question

a building in a city has a rectangular base. the length of the base measures 70 ft less than three times the width. the perimeter of this base is 940 ft. what are the dimensions of the base?

Answer 1

Perimeter of rectangle is : P = 2L + 2W
P = 940
L = 3W - 70
now we sub
940 = 2(3W - 70) + 2W --- distribute through the parenthesis
940 = 6W - 140 + 2W -- combine like terms
940 = 8W - 140 --- add 140 to both sides
940 + 140 = 8W
1080 = 8W -- divide both sides by 8
1080/8 = W
135 = W

L = 3W - 70
L = 3(135) - 70
L = 405 - 70
L = 335

check..
P = 2L + 2W
940 = 2(335) + 2(135)
940 = 670 + 270
940 = 940 (correct)

Length (L) = 335
Width (W) = 135