What are the factors of [tex]\( 8x^3 - 27y^3 \)[/tex]?

Select all the correct answers:

A. [tex]\( (2x - 3y) \)[/tex]

B. [tex]\( (2x + 3y) \)[/tex]

C. [tex]\( (4x^2 + 6xy + 9y^2) \)[/tex]

D. [tex]\( (4x^2 + 2xy - 6y^2) \)[/tex]

E. [tex]\( (4x^2 - 2xy + 9y^2) \)[/tex]



Answer :

To find the factors of the expression [tex]\(8x^3 - 27y^3\)[/tex], we start with recognizing that this expression represents a difference of two cubes. The general formula for factoring the difference of cubes is:

[tex]\[a^3 - b^3 = (a - b)(a^2 + ab + b^2)\][/tex]

In our case, we can rewrite [tex]\(8x^3\)[/tex] as [tex]\((2x)^3\)[/tex] and [tex]\(27y^3\)[/tex] as [tex]\((3y)^3\)[/tex]. Therefore, the expression [tex]\(8x^3 - 27y^3\)[/tex] can be expressed as:

[tex]\[ (2x)^3 - (3y)^3 \][/tex]

Applying the difference of cubes formula:
[tex]\[ a = 2x \quad \text{and} \quad b = 3y \][/tex]

Now we substitute [tex]\(2x\)[/tex] and [tex]\(3y\)[/tex] into the formula:
[tex]\[ (2x)^3 - (3y)^3 = (2x - 3y)((2x)^2 + (2x)(3y) + (3y)^2) \][/tex]

Simplifying inside the parentheses:
[tex]\[ = (2x - 3y)(4x^2 + 6xy + 9y^2) \][/tex]

Thus, the expression [tex]\(8x^3 - 27y^3\)[/tex] factors to:
[tex]\[ (2x - 3y)(4x^2 + 6xy + 9y^2) \][/tex]

Let's match our factors with the given options:

A. [tex]\((2x - 3y)\)[/tex] – Yes, this is a factor.
B. [tex]\((2x + 3y)\)[/tex] – No, this is not a factor.
C. [tex]\((4x^2 + 6xy + 9y^2)\)[/tex] – Yes, this is a factor.
D. [tex]\((4x^2 + 2xy - 6y^2)\)[/tex] – No, this is not a factor.
E. [tex]\((4x^2 - 2xy + 9y^2)\)[/tex] – No, this is not a factor.

So, the correct answers are:
A. [tex]\((2x - 3y)\)[/tex]
C. [tex]\((4x^2 + 6xy + 9y^2)\)[/tex]