Givens
Let the width = x
Let the length = x + 9
Area = 52 in^2
Formula
Area = L * W
Solve
52 = (x + 9)(x ) Remove the brackets.
52 = x^2 + 9x Subtract 52 from both sides
x^2 + 9x - 52 = 0 Factor
You need 2 numbers that add to 9 and multiply to 52. There aren't many
52 and 1
26 and 2
13 and 4
All three will multiply to 52. 52 = 52 + 1 or 52 - 1 (The larger number must be plus). 53 or 51 is not the sum. 52 and 1 is not the answer.
26 and 2 will add or subtract to 28 or 24. Neither 1 is 9. So that can't be your answer.
13 and 4 will give 9 or 17. There's your answer.
(x + 13)(x - 4) = 0
x = - 13 is not the answer. You cannot have minus distances.
x - 4 = 0
x = 4
The width is 4 inches <<<< answer.