Question

Factor the polynomial completely. 4x3 – 12x2 7x – 21 4x2(x – 3) 7(x – 3) Which is the completely factored polynomial? 4x2(x 4) 3x2(x – 3) (4x2 – 7)(x 3) (4x2 7)(x – 3).

Answer 1

(d) (4x² +7)(x -3)

Explanation:

This polynomial can be factored by factoring pairs of terms.

= (4x³ -12x²) +(7x -21)

= 4x²(x -3) +7(x -3)

= (4x² +7)(x -3)

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Additional comment

The answer choices suggest we're not interested in irrational or complex factors. The quadratic (4x² +7) could be factored into linear terms involving irrational complex numbers. The form for "difference of squares" would be used for the purpose.