Question

The length of a rectangle is 10 feet less then 4 times the width the perimeter is 50 feet. Find the length and the width

Answer 1

Perimeter = 2l + 2w

Length: 4w - 10

Width: w


50 = 2(4w-10) + 2w

50 = 8w - 20 + 2w

50 = 10w - 20

70 = 10w

7 = w

Length: 4(7) - 10 -----> 28 - 10 -----> 18


So, the width is 7 and the length is 18.

Checking the answers:

50 = 2l + 2w

50 = 2(18) + 2(7)

50 = 36 + 14

50 = 50

Answer 2

P = 2(L + W)
P = 50
L = 4W - 10

50 = 2(4W - 10 + W)
50 = 2(5W - 10)
50 = 10W - 20
50 + 20 = 10W
70 = 10W
70/10 = W
7 = W <=== width is 7 ft

L = 4W - 10
L = 4(7) - 10
L = 28 - 10
L = 18 <== length is 18 ft