What is the quotient of the rational expression below?

[tex]
\frac{x^2-36}{x+8} \div \frac{x^2+12x+36}{4x+32}
[/tex]

A. [tex]\frac{4(x-6)}{x+6}[/tex]

B. [tex]\frac{4x-6}{(x+6)^2}[/tex]

C. [tex]\frac{4(x+6)}{(x-6)}[/tex]

D. [tex]\frac{4x-6}{x+6}[/tex]



Answer :

To find the quotient of the given rational expressions:

[tex]\[ \frac{x^2 - 36}{x + 8} \div \frac{x^2 + 12x + 36}{4x + 32} \][/tex]

we need to follow these steps:

### Step 1: Rewrite the Division as Multiplication
Instead of dividing by the second rational expression, we multiply by its reciprocal:
[tex]\[ \frac{x^2 - 36}{x + 8} \times \frac{4x + 32}{x^2 + 12x + 36} \][/tex]

### Step 2: Factorize the Expressions
Factor each polynomial in the expressions:
- For [tex]\(x^2 - 36\)[/tex]:
[tex]\[ x^2 - 36 = (x - 6)(x + 6) \][/tex]
- For [tex]\(x^2 + 12x + 36\)[/tex]:
[tex]\[ x^2 + 12x + 36 = (x + 6)^2 \][/tex]
- For [tex]\(4x + 32\)[/tex]:
[tex]\[ 4x + 32 = 4(x + 8) \][/tex]

So the expression becomes:
[tex]\[ \frac{(x - 6)(x + 6)}{x + 8} \times \frac{4(x + 8)}{(x + 6)^2} \][/tex]

### Step 3: Simplify the Expression
Now, we can simplify by canceling out the common terms in the numerator and the denominator:
- The [tex]\(x + 8\)[/tex] terms cancel out.
- One [tex]\(x + 6\)[/tex] term in the numerator and [tex]\(x + 6\)[/tex] terms in the denominator cancel out.

After cancellation:
[tex]\[ \frac{(x - 6)}{1} \times \frac{4}{x + 6} = \frac{4(x - 6)}{x + 6} \][/tex]

### Step 4: Write Down the Simplified Quotient
The simplified quotient is:
[tex]\[ \frac{4(x - 6)}{x + 6} \][/tex]

So, the correct answer is:

[tex]\[ \boxed{\frac{4(x-6)}{x+6}} \][/tex]

This corresponds to option A.