1. **State the problem:** Simplify the expression $$\frac{x^2 - 25}{x^2 + 5x} \div \frac{xy + 6x - 5y - 30}{5x - 15}$$.
2. **Rewrite division as multiplication by the reciprocal:**
$$\frac{x^2 - 25}{x^2 + 5x} \times \frac{5x - 15}{xy + 6x - 5y - 30}$$
3. **Factor all polynomials:**
- Numerator top-left: $$x^2 - 25 = (x - 5)(x + 5)$$
- Denominator top-left: $$x^2 + 5x = x(x + 5)$$
- Numerator top-right (denominator of division): factor by grouping:
$$xy + 6x - 5y - 30 = x(y + 6) - 5(y + 6) = (x - 5)(y + 6)$$
- Denominator top-right (numerator of division): $$5x - 15 = 5(x - 3)$$
4. **Substitute factored forms:**
$$\frac{(x - 5)(x + 5)}{x(x + 5)} \times \frac{5(x - 3)}{(x - 5)(y + 6)}$$
5. **Multiply numerators and denominators:**
$$\frac{(x - 5)(x + 5) \times 5(x - 3)}{x(x + 5) \times (x - 5)(y + 6)}$$
6. **Cancel common factors:**
- Cancel $(x - 5)$ numerator and denominator
- Cancel $(x + 5)$ numerator and denominator
Intermediate step with cancellation:
$$\frac{\cancel{(x - 5)} \cancel{(x + 5)} \times 5(x - 3)}{x \cancel{(x + 5)} \times \cancel{(x - 5)} (y + 6)} = \frac{5(x - 3)}{x(y + 6)}$$
7. **Final simplified expression:**
$$\boxed{\frac{5(x - 3)}{x(y + 6)}}$$
This is the simplified form of the original expression.
Rational Expression Division 672Fdb
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