9514 1404 393
Answer:
Step-by-step explanation:
The area is the product of length and width:
A = LW
144 = (w+10)(w)
w^2 +10w -144 = 0 . . . . . . subtract 144 and put in standard form
(w +18)(w -8) = 0 . . . . . . . . factor
w = -18 or 8 . . . . . . . values that make the factors zero, -18 is extraneous
The width of the wall is 8 ft; the length is 18 ft.
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<em>Additional comment</em>
The equation is factored by looking for factors of -144 that have a sum of 10. We can choose from the different ways 144 can be factored:
-144 = -1(144) = -2(72) = -3(48) = -4(36) = -6(24) = -8(18) = -9(16) = -12(12)
The respective sums are 143, 70, 45, 32, 18, 10, 7, 0.
So, the factors of -144 that have a sum of 10 are {-8, 18}. These are the constants that go into the binomial factors.
