Which of the following is the product of the rational expressions shown below?

[tex]\[
\frac{x+2}{x-4} \cdot \frac{3x}{x+4}
\][/tex]

A. [tex]\(\frac{3x^2+6x}{x^2-16}\)[/tex]

B. [tex]\(\frac{3x^2+2x}{x-16}\)[/tex]

C. [tex]\(\frac{3x+6}{x^2-16}\)[/tex]

D. [tex]\(\frac{4x+2}{x^2}\)[/tex]



Answer :

To determine which of the provided options represents the product of the rational expressions [tex]\(\frac{x+2}{x-4} \cdot \frac{3 x}{x+4}\)[/tex], let us break down and simplify the given expressions step-by-step.

1. Identify and Multiply the Numerators:
The numerators of the given fractions are [tex]\(x + 2\)[/tex] and [tex]\(3x\)[/tex].
[tex]\[ (x + 2) \cdot (3x) \][/tex]
When we multiply these numerators, we distribute the terms inside the parentheses:
[tex]\[ x \cdot 3x + 2 \cdot 3x = 3x^2 + 6x \][/tex]

2. Identify and Multiply the Denominators:
The denominators of the given fractions are [tex]\(x - 4\)[/tex] and [tex]\(x + 4\)[/tex].
[tex]\[ (x - 4) \cdot (x + 4) \][/tex]
Notice that this is a difference of squares:
[tex]\[ (x - 4)(x + 4) = x^2 - 4^2 = x^2 - 16 \][/tex]

3. Construct the Combined Rational Expression:
Using the results from steps 1 and 2, the combined rational expression will be:
[tex]\[ \frac{3x^2 + 6x}{x^2 - 16} \][/tex]

Now, let’s match our simplified expression against the provided answer choices:

A. [tex]\(\frac{3 x^2+6 x}{x^2-16}\)[/tex]

B. [tex]\(\frac{3 x^2+2 x}{x-16}\)[/tex]

C. [tex]\(\frac{3 x+6}{x^2-16}\)[/tex]

D. [tex]\(\frac{4 x+2}{x^2}\)[/tex]

Clearly, option A matches the simplified form perfectly.

Thus, the product of the given rational expressions is:
[tex]\[ \boxed{\frac{3 x^2+6 x}{x^2-16}} \][/tex]
So, the correct choice is A.