SOLUTION: A rectangle has a perimeter of 56cm. The length is 4 less than 3 times width. Find its dimensions.

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Question 1115410: A rectangle has a perimeter of 56cm. The length is 4 less than 3 times width. Find its dimensions.
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

given:
A rectangle has a perimeter of 56cm.
=> P=2%28L%2BW%29
=> 2%28L%2BW%29=56cm
=> L%2BW=56cm%2F2
=> L%2BW=28cm
=> L=28cm-W....eq.1
if the length is 4cm less than 3 times width, we have:
L=3W-4cm...eq.2 ...substitute in eq.1

3W-4cm=28cm-W
3W%2BW=28cm%2B4cm
4W=32cm
W=32cm%2F4
highlight%28W=8cm%29
now find the length:
L=28cm-W....eq.1
L=28cm-8cm
highlight%28L=20cm%29
so, dimensions are:highlight%28L=20cm%29,highlight%28W=8cm%29