Question

The Johnsons framed a family picture to hang on the wall. The perimeter of the frame is 72 inches. Use the formula P = 2ℓ + 2w to find the length of the frame if the width is 19 inches.

17 in.

19 in.

15 in.

20 in
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I think it's 17 inches.

Answer 1

`P=2l+2w\\\\\text{We have}\ P=72\ in\ \text{and}\ w=19\ in.\\\\\text{Substitute:}\\\\2l+2(19)=72\\\\2l+38=72\qquad\text{subtract 38 from both sides}\\\\2l=34\qquad\text{divide both sides by 2}\\\\\boxed{l=17}\\\\Answer:\ \boxed{17\ in}`

Answer 2

P = 2l+2w

substitute P and w

72 = 2l + 2(19)

72 = 2l + 38

subtract 38 from each side

72-38 = 2l + 38-38

34 = 2l

divide by 2

34/2 = 2l/2

17 = l

L = 17 inches