Question

21x^3 + 6x^2 - 28x - 8

Answer 1

In this question, we need to factor the polynomial.

`\begin{gathered} 21x^3+6x^2\text{ - 28 x - 8} \\ \end{gathered}`

Factoring:

`21x^3+6^{}x^2\text{ - 28 x 8}`

First, we split the expression at hand into groups, each group having two terms :

`\begin{gathered} \text{Group 1 : -28 x - 8} \\ \text{Group 2 : 21 x}^3+6x^2 \end{gathered}`

Pull out from each group separately :

Group 1: (7x+2) • (-4)

Group 2: (7x+2) • (3x^2)

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Add up the two groups :

`(7x+2)(3x^2\text{ - 4 )}`

Which is the desired factorization