12. Multiply:

[tex]\[
\frac{q+5}{2} \cdot \frac{4q}{q+4}
\][/tex]

Choose the correct simplified form:

A. [tex]\(\frac{4q+20q^2}{4q+8}\)[/tex]

B. [tex]\(\frac{4q^2+20q}{2}\)[/tex]

C. [tex]\(\frac{q^2+20q}{2q}\)[/tex]

D. [tex]\(\frac{4q^2+20q}{2q+8}\)[/tex]



Answer :

Certainly! Let's go step-by-step to multiply these fractions and ultimately simplify the product.

We are given the following fractions to multiply:

1. [tex]\(\frac{q + 5}{2}\)[/tex]
2. [tex]\(\frac{4q}{q + 4}\)[/tex]
3. [tex]\(\frac{4q + 20q^2}{4q + 8}\)[/tex]
4. [tex]\(\frac{4q^2 + 20q}{2}\)[/tex]
5. [tex]\(\frac{q^2 + 20q}{2q}\)[/tex]
6. [tex]\(\frac{4q^2 + 20q}{2q + 8}\)[/tex]

Let's now multiply these fractions together:

[tex]\[ \frac{q + 5}{2} \cdot \frac{4q}{q + 4} \cdot \frac{4q + 20q^2}{4q + 8} \cdot \frac{4q^2 + 20q}{2} \cdot \frac{q^2 + 20q}{2q} \cdot \frac{4q^2 + 20q}{2q + 8} \][/tex]

### Step 1: Combine the fractions
Combine the numerators and the denominators.

[tex]\[ \frac{(q + 5) \cdot 4q \cdot (4q + 20q^2) \cdot (4q^2 + 20q) \cdot (q^2 + 20q) \cdot (4q^2 + 20q)}{2 \cdot (q + 4) \cdot (4q + 8) \cdot 2 \cdot 2q \cdot (2q + 8)} \][/tex]

### Step 2: Simplify each component
Let's now simplify each component individually:

- [tex]\(4q + 20q^2 = 4q(1 + 5q) = 4q(5q + 1)\)[/tex]
- [tex]\(4q + 8 = 4(q + 2)\)[/tex]
- [tex]\(4q^2 + 20q = 4q(q + 5)\)[/tex]
- [tex]\(q^2 + 20q = q(q + 20)\)[/tex]
- [tex]\(2q + 8 = 2(q + 4)\)[/tex]

### Step 3: Substitute back into fractions
Substituting these simplified forms back:

[tex]\[ \frac{(q + 5) \cdot 4q \cdot 4q(5q + 1) \cdot 4q(q + 5) \cdot q(q + 20) \cdot 4q(q + 5)}{2 \cdot (q + 4) \cdot 4(q + 2) \cdot 2 \cdot 2q \cdot 2(q + 4)} \][/tex]

### Step 4: Combine and simplify the overall fraction
Combine the terms:

[tex]\[ \frac{4 \cdot 4 \cdot 4 \cdot 4 \cdot q \cdot q \cdot q \cdot q \cdot (q + 5) \cdot (q + 5) \cdot (5q + 1) \cdot (q + 5) \cdot (q + 20) \cdot (q + 5)}{2 \cdot 4 \cdot 4 \cdot 2 \cdot 2q \cdot (q + 4) \cdot (q + 2) \cdot (q + 4)} \][/tex]

This simplifies to:

[tex]\[ \frac{4^4 \cdot q^4 \cdot (q + 5)^3 \cdot (5q + 1) \cdot (q + 20)}{2^4 \cdot q \cdot (q + 4)^2 \cdot (q + 2)} \][/tex]

We know that [tex]\(4 = 2^2\)[/tex], so [tex]\(4^4 = (2^2)^4 = 2^8\)[/tex]:

[tex]\[ \frac{2^8 \cdot q^4 \cdot (q + 5)^3 \cdot (5q + 1) \cdot (q + 20)}{2^4 \cdot q \cdot (q + 4)^2 \cdot (q + 2)} \][/tex]

Finally, cancel out common factors [tex]\(2^4\)[/tex]:

[tex]\[ \frac{2^{8-4} \cdot q^4 \cdot (q + 5)^3 \cdot (5q + 1) \cdot (q + 20)}{q \cdot (q + 4)^2 \cdot (q + 2)} \][/tex]

### Final Simplified Form

[tex]\[ \frac{4q^4 (q + 5)^3 (5q + 1) (q + 20)}{(q + 2)(q + 4)^2} \][/tex]

Thus, the simplified form of the product of the given fractions is:

[tex]\[ \frac{4q^4 (q + 5)^3 (q + 20)(5q + 1)}{(q + 2)(q + 4)^2} \][/tex]