The length of a rectangle is 5 centimeters less than 3 times the width. The perimeter of the rectangle is 160 centimeters. Find the dimensions of the rectangle.

Question

I need help

Answer 1

Let L = length and W = width

Length is 5 cm less than 3 * W; L = 3W - 5

Perimeter = 2(L + W) = 160; 160 = 2(L + W)

 

Divide the perimeter equation by 2

80 = L + W

Substitute: 80 = 3W -5 + W => 4W = 85 and W = 21.25 and L = 58.75

Answer 2

The length of a rectangle is 5 centimeters less than 3 times the width

l = 3w - 5

The perimeter of the rectangle is 160 centimeters.

P = 2l + 2w

Substitute:

160 = 2(3w - 5) + 2w

160 = 6w - 10 + 2w

160 = 8w - 10

170 = 8w

w = 21.25

l = 58.75