Find the width and length

The length of a rectangle is 4 m longer than its width. If the perimeter of the rectangle is 72 m, find its length and width.

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Perimeter of a rectangle = 2(width) + 2(length)

w = width
w + 4 = length {length is 4 longer than width}

2w + 2(w + 4) = 72 {substituted width, length, and perimeter into perimeter formula}
2w + 2w + 8 = 72 {used distributive property}
4w + 8 = 72 {combined like terms}
4w = 64 {subtracted 8 from each side}
w = 16 {divided each side by 4}
w + 4 = 20 {substituted 16, in for w, into w+ 4}

width = 16
length = 20

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