SOLUTION: The width of a rectangle is 4 cm less then the length. The perimeter is 72 cm. What is the width of the rectangle?

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Question 260084: The width of a rectangle is 4 cm less then the length. The perimeter is 72 cm. What is the width of the rectangle?

Found 2 solutions by dabanfield, checkley77:
Answer by dabanfield(803) About Me  (Show Source):
You can put this solution on YOUR website!
The width of a rectangle is 4 cm less then the length. The perimeter is 72 cm. What is the width of the rectangle?
Let l be the length and w the width of the rectangle. Then the perimeter = 2*l + 2*w
We also know that w = l - 4 or equivalently l = w + 4:
Perimeter = 72 = 2*l + 2*w.
Substituting w + 4 for l in the equation above we have:
72 = 2*(w+4) + 2*w
Solve the above for w.

Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
W=L-4
2W+2L=72
2(L-4)+2L=72
2L-8+2L=72
4L=72+8
4L=80
L=80/4
L=20 ANS. FOR THE LENGTH.
W=20-4=16 ANS. FOR THE WIDTH.
PROOF:
2*16+2*20=72
32+40=72
72=72