Factor the polynomial.
x² + 6x + 9
Find factors of 9 that, when the factors are added, will give you 6.
x² + 6x + 9
x² = x(x)
9 = 3(3)
(x + 3)(x + 3)
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(x + 3)(x + 3), or (A) is your answer
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hope this helps