w(w + 11) = 900
w2 + 11w - 900 = 0
1(-900) = -900
What two factors of -900 add up to 11?
-9 and 100? Not even close.
Ahhh, 36 and -25.
w2 + 36w - 25w - 900 = 0
w(w + 36) - 25(w + 36) = 0
(w - 25)(w + 36) = 0
For the left side to equal 0, w - 25 or w + 36 has to equal 0.
w - 25 = 0
w = 25
25 + 11 = 36
w + 36 = 0
w = -36
Because we measure using positive numbers, we disregard this "answer."
The length is 36" and the width is 25".