SOLUTION: The length of a rectangle is 3 1/2 times its width. It's perimeter is 108cm. Find it's length and width. Choices for the width: 12, 18, 24 I'm seriously stuck. My math teacher d

Algebra ->  Expressions-with-variables -> SOLUTION: The length of a rectangle is 3 1/2 times its width. It's perimeter is 108cm. Find it's length and width. Choices for the width: 12, 18, 24 I'm seriously stuck. My math teacher d      Log On


   

Question 487981: The length of a rectangle is 3 1/2 times its width. It's perimeter is 108cm. Find it's length and width. Choices for the width: 12, 18, 24
I'm seriously stuck. My math teacher didn't teach us how to do this. He just gave us our assignment and told us it was hard.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The length of a rectangle is 3 1/2 times its width.
It's perimeter is 108cm. Find it's length and width.
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Let the width be "x"
Then the length is (7/2)x.
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Perimeter = 2(length + width)
108 = 2((7/2)x + x)
54 = (9/2)x
x = (2/9)(54)
x = 2*6 = 12 (width)
length = (7/2)x = (7/2)12 = 7*6 = 42
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Cheers,
Stan H.
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Choices for the width: 12, 18, 24