A square has one dimension increased by 4 feet and another dimension decreased by 2 feet. If the resulting rectangle has an area of 72 square feet, which of the following equations could be used to solve for the square's original side length, x?

Question

4462 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-03-26T05:08:53

Let the side of the square be #x# feet

One side is increased by 4 feet #=> x+4# feet

Other side is decreased by 2 feet.#=> x-2# feet

area of resulting rectangle #=> 72 # sq feet

#=> (x+4)(x-2) = 72#
#=> x^2 +4x -2x - 8 =72#
#=> x^2 +2x - 80 =0#
#=> x^2 +10x -8x- 80 =0#
#=> x(x +10) -8(x+ 10) =0#
#=> (x+10)(x-8) = 0#

therefore, #x=8 or -10#

since length cant be negative, #x=8#

Side of the square is 8 feet.