SOLUTION: The length of a rectangle is 6 centimeters less than twice its width. The perimeter of the rectangle is 30 centimeters. What are the dimensions of the rectangle? Its a multiple

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Question 764753: The length of a rectangle is 6 centimeters less than twice its width. The perimeter of the rectangle is 30 centimeters. What are the dimensions of the rectangle?
Its a multiple choice question.
A. length= 5 cm; width= 10 cm B. length= 12 cm; width= 9 cm
C. length= 8 cm; width= 7 cm D. length= 7 cm; width= 8 cm
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

given:
The length of a rectangle is 6cm less than twice its width:
then we have length+%2B6cm=2%2Awidth........eq.1
the perimeter of the rectangle is 30cm:
P=2%2Alength%2B2%2Awidth
if P=30cm, then 2%2Alength%2B2%2Awidth=30cm .....eq.2
now substitute 2%2Awidth from eq.1 in eq.2
2%2Alength%2B%28length+%2B6cm%29=30cm......solve for length
3%2Alength+=30cm-6cm
3%2Alength+=24cm
length+=24cm%2F3
highlight%28length+=8cm%29
now go back to eq.1 and find the width

length+%2B6cm=2%2Awidth........eq.1......plug in length
8cm%2B6cm=2%2Awidth
14cm=2%2Awidth
width=14cm%2F2
highlight%28width=7cm%29
so, your answer is C. length=+8cm; width=+7cm