SOLUTION: The perimeter of a rectangle is 126 cm. The ratio of the length to the width is 5:2. Find the width of the rectangle.

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Question 395684: The perimeter of a rectangle is 126 cm. The ratio of the length to the width is 5:2. Find the width of the rectangle.
Found 2 solutions by Alan3354, MathLover1:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The perimeter of a rectangle is 126 cm. The ratio of the length to the width is 5:2. Find the width of the rectangle.
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L + W = 1/2 the perimeter = 63 cm
5 + 2 = 7
63/7 = 9
Width = 2*9 = 18 cm

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

let the length be a, and the width be b
given:
P+=126cm
a%3Ab=5%3A2......=> 2a=5b.......=>.......a=5b%2F2

P+=126cm
126cm=2%28a%2Bb%29.......substitute a=5b%2F2
126cm=2%28%285b%2F2%29%2Bb%29
126cm=%2810b%2F2%29%2B2b%29
126cm=%28cross%2810%295b%2Fcross%282%29%29%2B2b%29
126cm=+5b%2B2b
126cm=+7b
126cm%2F7=+b
18cm=+b.............now find a

a=5b%2F2
a=5%2A%2818cm%29%2F2

a=5%2A%28cross%2818%29cm%29%2Fcross%282%29
a=5%2A%289cm%29
a=+45cm
check:
126cm=2%28a%2Bb%29
126cm=2%2845cm%2B18cm%29
126cm=2%2863cm%29
126cm=126cm%29