The Ogburn School
Alg2_Trig_MCLA

Turning in Your Work!

You must turn in your homework for credit.
All practice work must include the Session Code, Time, Topic, and Instructor name.

- Session Code: Alg2 0620
- Session Time: 4:30
- Session Topic: Multiply/Divide Rational Expressions
- Instructor: Mrs. Vega

Fill in the blue boxes only with the missing values:

[tex]\[
\begin{array}{l}
\frac{m^2-9}{m^2+5m+6} \div \frac{3-m}{m+2} = \frac{m^2-9}{m^2+5m+6} \cdot \frac{(m-3)(m+3)}{(m+3)(m+2)} \cdot \frac{(m+2)}{(3-m)} \\
\frac{(m-3)}{(3-m)}=\frac{(m+2)}{(3-m)}=4
\end{array}
\][/tex]

Practice work must be submitted within 7 days to receive credit for today's session.



Answer :

Certainly! Let's go through this problem step-by-step to fully understand the process of simplifying the given expression.

The problem involves dividing and then multiplying rational expressions. Let’s go through it step-by-step:

1. Given Expression:

[tex]\[\frac{m^2-9}{m^2+5m+6} \div \frac{3-m}{m+2}\][/tex]

2. Rewrite the Division as Multiplication:

When dividing by a fraction, you multiply by its reciprocal.

[tex]\[\frac{m^2-9}{m^2+5m+6} \div \frac{3-m}{m+2} = \frac{m^2-9}{m^2+5m+6} \cdot \frac{m+2}{3-m}\][/tex]

3. Factorize the Numerator and Denominator:

Let's factorize each part:

- Numerator [tex]\(m^2 - 9\)[/tex] is a difference of squares:

[tex]\[m^2 - 9 = (m - 3)(m + 3)\][/tex]

- Denominator [tex]\(m^2 + 5m + 6\)[/tex] can be factored as:

[tex]\(m^2 + 5m + 6 = (m + 2)(m + 3)\)[/tex]

4. Rewrite the Expression with Factored Forms:

Substitute the factored forms into the expression:

[tex]\[\frac{(m - 3)(m + 3)}{(m + 2)(m + 3)} \cdot \frac{m + 2}{3 - m}\][/tex]

5. Simplify:

Notice in the expression [tex]\(3 - m\)[/tex], we can rewrite it as [tex]\(-(m - 3)\)[/tex]:

[tex]\[\frac{(m - 3)(m + 3)}{(m + 2)(m + 3)} \cdot \frac{m + 2}{-(m - 3)}\][/tex]

6. Cancellation:

Before multiplying, look for and cancel common factors in the numerator and denominator:

The [tex]\((m + 3)\)[/tex] and [tex]\((m + 2)\)[/tex] terms will cancel each other out in the numerator and denominator:

[tex]\[\frac{(m - 3) \cancel{(m + 3)}}{\cancel{(m + 2)} \cancel{(m + 3)}} \cdot \frac{\cancel{(m + 2)}}{-(m - 3)}\][/tex]

This simplifies to:

[tex]\[\frac{m - 3}{- (m - 3)}\][/tex]

7. Further Simplification:

Recognize that:

[tex]\(\frac{m - 3}{- (m - 3)} = -1\)[/tex]

8. Square Term Simplification:

When squaring [tex]\( \frac{(m-3)}{(m + 2)} \)[/tex]:

[tex]\((m - 3)^2\ / (m + 2)^2\)[/tex]

So the final step would include multiplying by [tex]\(-1\)[/tex]:

[tex]\[\boxed{\frac{(m - 3)^2}{(m + 2)^2} \cdot -1}\][/tex]

Thus, the simplified final expression is:

[tex]\[ \boxed{ -\frac{(m - 3)^2}{(m + 2)^2}} \][/tex]