Factorize x2 + 9x + 20
-
A.
(x − 5) 2 -
B.
(x + 5)(x + 4) -
C.
(x – 5)(x + 3) -
D.
(x + 3) 2
Correct Answer: Option B
Explanation
( x^2 + 9x + 20 )
Find the two numbers whose product is 20 and its sum is 9}
( 5x times 4x = 20x^2)
(5x + 4x = 9x)
((x^2 + 5x) + (4x + 20))
(
x(x + 5)+ 4(x + 5)
= (x + 5)(x + 4))
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