Which shows one way to determine the factors of [tex]$12x^3 - 2x^2 + 18x - 3$[/tex] by grouping?

A. [tex]2x^2(6x - 1) + 3(6x - 1)[/tex]
B. [tex]2x^2(6x - 1) - 3(6x - 1)[/tex]
C. [tex]6x(2x^2 - 3) - 1(2x^2 - 3)[/tex]
D. [tex]6x(2x^2 + 3) + 1(2x^2 + 3)[/tex]



Answer :

To determine which expression shows one way to factorize the polynomial [tex]\(12x^3 - 2x^2 + 18x - 3\)[/tex] by grouping, we will evaluate each option to see which correctly simplifies back to the given polynomial.

### Option 1: [tex]\(2x^2(6x - 1) + 3(6x - 1)\)[/tex]

Let's expand this:

[tex]\[ 2x^2(6x - 1) + 3(6x - 1) = 2x^2 \cdot 6x + 2x^2 \cdot (-1) + 3 \cdot 6x + 3 \cdot (-1) \][/tex]

[tex]\[ = 12x^3 - 2x^2 + 18x - 3 \][/tex]

This expansion matches the given polynomial [tex]\(12x^3 - 2x^2 + 18x - 3\)[/tex]. So, Option 1 correctly factorizes the polynomial through grouping.

### Option 2: [tex]\(2x^2(6x - 1) - 3(6x - 1)\)[/tex]

Let's expand this:

[tex]\[ 2x^2(6x - 1) - 3(6x - 1) = 2x^2 \cdot 6x + 2x^2 \cdot (-1) - 3 \cdot 6x - 3 \cdot (-1) \][/tex]

[tex]\[ = 12x^3 - 2x^2 - 18x + 3 \][/tex]

This expansion gives [tex]\(12x^3 - 2x^2 - 18x + 3\)[/tex], which does not match the given polynomial. Therefore, Option 2 is incorrect.

### Option 3: [tex]\(6x(2x^2 - 3) - 1(2x^2 - 3)\)[/tex]

Let's expand this:

[tex]\[ 6x(2x^2 - 3) - 1(2x^2 - 3) = 6x \cdot 2x^2 + 6x \cdot (-3) - 1 \cdot 2x^2 - 1 \cdot (-3) \][/tex]

[tex]\[ = 12x^3 - 18x - 2x^2 + 3 \][/tex]

This expansion gives [tex]\(12x^3 - 18x - 2x^2 + 3\)[/tex], which does not match the given polynomial. Therefore, Option 3 is incorrect.

### Option 4: [tex]\(6x(2x^2 + 3) + 1(2x^2 + 3)\)[/tex]

Let's expand this:

[tex]\[ 6x(2x^2 + 3) + 1(2x^2 + 3) = 6x \cdot 2x^2 + 6x \cdot 3 + 1 \cdot 2x^2 + 1 \cdot 3 \][/tex]

[tex]\[ = 12x^3 + 18x + 2x^2 + 3 \][/tex]

This expansion gives [tex]\(12x^3 + 18x + 2x^2 + 3\)[/tex], which does not match the given polynomial. Therefore, Option 4 is incorrect.

Thus, the correct way to determine one way to factorize [tex]\(12x^3 - 2x^2 + 18x - 3\)[/tex] by grouping is:

[tex]\[ \boxed{2x^2(6x - 1) + 3(6x - 1)} \][/tex]