The length of a rectangle is four times its width. If the area is 100 m2 what is the length of the rectangle?  Choices:
A) 60 m B) 50 m C) 40 m D) 30 m E) 20 m
Let L be the length and W be the width of the rectangle. Hence   L = 4 W   We now use the area to write   100 = L * W   Substitute L by 4 W in the equation above   100 = 4 W * W = 4 W2   Solve for W and find L   4 W2 = 100   W2 = 25 , W = 5 and L = 4 W = 20 m   correct answer 20 m
<result>E</result>
The length of a rectangle is four times its width. If the area is 100 m2 what is the length of the rectangle?