Question

The perimeter of a rectangle is one more than the area of the rectangle. Find the area of the rectangle, if its width is 3 cm.
Answer

5 cm2

16 cm2

225 cm2

15 cm2

Answer 1

A = width x length
P= 2(width +length)

1 + Area = Perimeter
Width = 3

I believe the answer is 15cm2

Answer 2

Formulas for the area and perimeter of a rectangle
A = LW ----equation 1
P = 2L + 2W ----equation 2
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Given that the perimeter is 1 more than the area, you'll have the expression as:
A + 1 = P ----equation 3
and that W=3cm
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Expressing equation 3 in terms of L and W by substituting equations 1 and 2 you'll have:
A + 1 = P
(LW) + 1 = (2L + 2W)
LW + 1 = 2L + 2W
Since W=3cm, then we'll substitute to find the value of L
L(3) + 1 = 2L + 2(3)
3L + 1 = 2L + 6
Transpose 2L to the left side and 1 to the right side
3L - 2L = 6 - 1
Simplify
L = 5
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To find the area, go back to equation 1
A = LW
W = 3 and L = 5
A= 5cm(3cm)
A = 15cm^2