Questions: Divide and simplify the following rational expression.
(x^2-15x+56)/(x^2+17x+72) ÷ (x-8)/(x+9)
Give your answer as a reduced rational expression.
Transcript text: Divide and simplify the following rational expression.
\[
\frac{x^{2}-15 x+56}{x^{2}+17 x+72} \div \frac{x-8}{x+9}
\]
Give your answer as a reduced rational expression.
Solution
Solution Steps
Step 1: Factor the Polynomials
We start by factoring the polynomials in the given rational expression:
The numerator \( x^2 - 15x + 56 \) factors to:
\[
(x - 8)(x - 7)
\]
The denominator \( x^2 + 17x + 72 \) factors to:
\[
(x + 8)(x + 9)
\]
The expression \( x - 8 \) remains as is since it is already factored.
The expression \( x + 9 \) also remains as is.
Step 2: Formulate the Rational Expression
The original expression can be rewritten using the factored forms:
\[
\frac{(x - 8)(x - 7)}{(x + 8)(x + 9)} \div \frac{x - 8}{x + 9}
\]
This division can be transformed into multiplication by taking the reciprocal:
\[
\frac{(x - 8)(x - 7)}{(x + 8)(x + 9)} \cdot \frac{x + 9}{x - 8}
\]
Step 3: Simplify the Expression
Now, we can simplify the expression:
The \( (x - 8) \) terms in the numerator and denominator cancel out:
\[
\frac{(x - 7)(x + 9)}{(x + 8)}
\]
Step 4: Final Simplification
The simplified expression is:
\[
\frac{x - 7}{x + 8}
\]
Final Answer
The reduced rational expression is:
\[
\boxed{\frac{x - 7}{x + 8}}
\]