Question

Factor completely x3 + 7x2 + 3x + 21.

(x − 7)(x2 − 3)
(x + 7)(x2 + 3)
(x − 7)(x2 + 3)
(x + 7)(x2 − 3)

Answer 1

Its B.

Explanation:

Answer 2

(x + 7)(x^2 + 3)

Explanation:

The two constant terms in the binomials must have a positive product, so both will have the same sign. This eliminates the last two choices.

The coefficient of x^2 is +7, which eliminates the first choice.

The factorization is shown by the second choice:

(x + 7)(x^2 + 3)

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A caret (^) is used to signify an exponent.