Multiply. State the product in simplest form.

[tex]\[ \frac{45y}{y^2-4} \cdot \frac{y^2+2y}{18y^2} \][/tex]

A. [tex]\(\frac{5y}{2y^2-4y}\)[/tex]
B. [tex]\(\frac{10}{y-2}\)[/tex]
C. [tex]\(\frac{-5}{4}\)[/tex]
D. [tex]\(\frac{5}{2y-4}\)[/tex]



Answer :

To solve the multiplication of the given expressions and simplify it to its simplest form, follow these steps:

1. Write down the expressions:

[tex]\[ \frac{45 y}{y^2 - 4} \cdot \frac{y^2 + 2y}{18 y^2} \][/tex]

2. Factorize the denominators and numerators where possible:

- The first expression [tex]\( \frac{45 y}{y^2 - 4} \)[/tex]:
[tex]\[ y^2 - 4 \text{ can be factored as } (y - 2)(y + 2) \][/tex]
So, the expression becomes:
[tex]\[ \frac{45 y}{(y - 2)(y + 2)} \][/tex]

- The second expression [tex]\( \frac{y^2 + 2y}{18 y^2} \)[/tex]:
[tex]\[ y^2 + 2y \text{ can be factored as } y(y + 2) \][/tex]
So, the expression becomes:
[tex]\[ \frac{y(y + 2)}{18 y^2} \][/tex]

3. Substitute the factored forms into the original multiplication:

[tex]\[ \frac{45 y}{(y - 2)(y + 2)} \cdot \frac{y(y + 2)}{18 y^2} \][/tex]

4. Multiply the numerators together and the denominators together:

Numerator:
[tex]\[ 45 y \cdot y (y + 2) = 45 y^2 (y + 2) \][/tex]

Denominator:
[tex]\[ (y - 2)(y + 2) \cdot 18 y^2 = 18 y^2 (y - 2)(y + 2) \][/tex]

So, the expression becomes:
[tex]\[ \frac{45 y^2 (y + 2)}{18 y^2 (y - 2)(y + 2)} \][/tex]

5. Cancel out common factors in the numerator and denominator:

- The [tex]\( y + 2 \)[/tex] terms in the numerator and denominator cancel out.
- The [tex]\( y^2 \)[/tex] terms in the numerator and denominator cancel out.
- Simplify [tex]\(\frac{45}{18}\)[/tex]:

[tex]\[ \frac{45}{18} = \frac{45 \div 9}{18 \div 9} = \frac{5}{2} \][/tex]

6. Simplify the remaining expression:

After canceling out the common factors, the expression simplifies to:
[tex]\[ \frac{5}{2(y - 2)} \][/tex]

7. Write the final simplified product:

[tex]\[ \frac{5}{2(y - 2)} \][/tex]

Thus, the product of [tex]\( \frac{45 y}{y^2 - 4} \cdot \frac{y^2 + 2y}{18 y^2} \)[/tex] in its simplest form is:

[tex]\[ \frac{5}{2(y - 2)} \][/tex]