Which shows one way to determine the factors of [tex]$4x^3 + x^2 - 8x - 2$[/tex] by grouping?

A. [tex]x^2(4x + 1) - 2(4x + 1)[/tex]
B. [tex]x^2(4x - 1) + 2(4x - 1)[/tex]
C. [tex]4x^2(x + 2) - 1(x + 2)[/tex]
D. [tex]4x^2(x - 2) - 1(x - 2)[/tex]



Answer :

Let's determine the factors of the given polynomial [tex]\( 4x^3 + x^2 - 8x - 2 \)[/tex] by grouping.

1. Given polynomial:
[tex]\[ 4x^3 + x^2 - 8x - 2 \][/tex]

2. Group terms to facilitate factoring:
[tex]\[ (4x^3 + x^2) + (-8x - 2) \][/tex]

3. Factor out the greatest common factor from each group:
- For the first group, [tex]\( 4x^3 + x^2 \)[/tex]:
[tex]\[ x^2(4x + 1) \][/tex]
- For the second group, [tex]\( -8x - 2 \)[/tex]:
[tex]\[ -2(4x + 1) \][/tex]

4. Now, we can rewrite the polynomial:
[tex]\[ x^2(4x + 1) - 2(4x + 1) \][/tex]

5. Notice that [tex]\( 4x + 1 \)[/tex] is a common factor:
[tex]\[ (4x + 1)(x^2 - 2) \][/tex]

So, the polynomial [tex]\( 4x^3 + x^2 - 8x - 2 \)[/tex] is factored by grouping as:
[tex]\[ x^2(4x + 1) - 2(4x + 1) \][/tex]

Thus, the correct answer is:
[tex]\[ \boxed{x^2(4x + 1) - 2(4x + 1)} \][/tex]