Question

Write an equation to solve the following. Show all your work, including the steps for solving the equation and checking your answer. Clearly state your answer.

The perimeter of a rectangular photo is 72 cm. The length is twice the width.
What are the length and width of the photo?
(Hint: The formula for perimeter is 2w + 2l = P where w is the width, l is the length, and P is the perimeter.)
Answer:

Answer 1

The perimeter is 72 and P=2(L+W), furthermore, L=2W so altogether...

2(L+W)=72 and using L=2W in this we have:

2(2W+W)=72

3W=36

W=12 and since L=2W

L=24

So the length is 24cm and the width is 12cm.