A rectangle has a perimeter of 24 inches. What are its dimensions if its length is 3 inches greater than its width?

1 Answer
mrcoffie
Mar 3, 2018

The shorter side is 4.5 inches, the longer is 7.5 inches.

Explanation:

The perimeter formula for a rectangle is #P = 2l + 2w#
(Perimeter = 2 length + 2width)
Let #x# = width, then the length is 3 inches greater than the width, so
Let #x + 3# = length.

Substitute into the formula to get:

#24 = 2(x+3) + 2(x)#

Simplify (distribute then collect like terms) to:

#24 = 4x+6#

Solve this for #x#:

#\ 24 = 4x+6#
#-6 \ \ \ \ \ \ \ \ \ \ -6#
#\ 18 =4x#
#4.5 = x#
#x + 3 = 7.5#

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