SOLUTION: The length of a rectangle is 8 in. more than twice its width. The perimeter of the rectangle of 70 in. Find the length and with of the rectangle.

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Question 168683: The length of a rectangle is 8 in. more than twice its width. The perimeter of the rectangle of 70 in. Find the length and with of the rectangle.
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let L = the length and W = the width.
The perimeter of a rectactangle is given by:
P+=+2%28L%2BW%29
From the problem, you have L = 2W+8 (The length is 8 in. more than twice its width). And P = 70 in. Substitute these for L and P in the formula.
70+=+2%28%282W%2B8%29%2BW%29 Simplify.
70+=+2%283W%2B8%29
70+=+6W%2B16 Subtract 16 from both sides.
54+=+6W Divide both sides by 6.
9+=+W and
L+=+2W%2B8
L+=+2%289%29%2B8
L+=+18%2B8
L+=+26
The length is 26 in. and the width is 9 in.
Check:
P+=+2%28L%2BW%29 Substitute L = 26 and W = 9
P+=+2%2826%2B9%29
P+=+2%2835%29
P+=+70 It checks!