A banner maker was asked to redesign a squarebanner by increasing the width by 4 feet anddecreasing the length by 2 feet. The total area of thenew banner was 91 square feet.What was the length of the side of the original squarebanner?
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Let:
x = original sides.
x + 4 = new width
x - 2 = new feet
So:
(x + 4)(x - 2) = 91
x² - 2x + 4x - 8 - 91 = 0
x² + 2x - 99 = 0
Factoring:
(x + 11)(x - 9) = 0
x = -11 (the lenght can't be negative so this answer is not valid)
x = 9 ft