Question

Okay I know I suck at math and I really don't understand math that well so can you help me on this??? Thank you!







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

w - width
l - length
p - perimeter

The perimeter is 72 cm (p=72).
The length is twice the width (l=2w).
The formula for perimeter is 2w+2l=P.


`p=72 \\ l=2w \\ \\ 2w+2l=p \\ 2w+2 \cdot 2w=72 \\ 2w+4w=72 \\ 6w=72 \\ w=12 \\ \\ l=2w=2 \cdot 12 =24`

Check the answer:

`2 \cdot 12 + 2 \cdot 24 \stackrel{?}{=} 72 \\ 24+48 \stackrel{?}{=} 72 \\ 72 \stackrel{?}{=} 72 \\ \hbox{true}`

The length of the photo is 24 cm, the width of the photo is 12 cm.