Teresa is factoring this polynomial by grouping. Which common factors should be used in the next step of factoring?

[tex]\[
\begin{array}{l}
10 x^3 + 3 x^2 - 20 x - 6 \\
\left(10 x^3 + 3 x^2\right) + \left(-20 x - 6\right)
\end{array}
\][/tex]

A. [tex]\( x^2 \)[/tex] and [tex]\(-2x\)[/tex]

B. [tex]\( 2x^2 \)[/tex] and [tex]\(-2x\)[/tex]

C. [tex]\( x^2 \)[/tex] and [tex]\(-2\)[/tex]

D. [tex]\( 2x^2 \)[/tex] and [tex]\(-2\)[/tex]



Answer :

To factor the polynomial [tex]\(10x^3 + 3x^2 - 20x - 6\)[/tex] by grouping, follow these steps carefully:

1. Look at the polynomial and split it into two groups:
[tex]\[ \left(10x^3 + 3x^2\right) + \left(-20x - 6\right) \][/tex]

2. Factor out the common factor from each group:
- In the first group [tex]\(\left(10x^3 + 3x^2\right)\)[/tex], the common factor is [tex]\(x^2\)[/tex]:
[tex]\[ 10x^3 + 3x^2 = x^2(10x + 3) \][/tex]
- In the second group [tex]\(\left(-20x - 6\right)\)[/tex], the common factor is [tex]\(-2\)[/tex]:
[tex]\[ -20x - 6 = -2(10x + 3) \][/tex]

3. Write the polynomial grouping with the common factors factored out:
[tex]\[ x^2(10x + 3) - 2(10x + 3) \][/tex]

Given the choices provided:
1. [tex]\(x^2\)[/tex] and [tex]\(-2x\)[/tex]
2. [tex]\(2x^2\)[/tex] and [tex]\(-2x\)[/tex]
3. [tex]\(x^2\)[/tex] and [tex]\(-2\)[/tex]
4. [tex]\(2x^2\)[/tex] and [tex]\(-2\)[/tex]

The correct common factors to use in the next step of factoring are:
[tex]\[ x^2 \text{ and } -2 \][/tex]