1. **State the problem:** Simplify the expression $$\frac{15x^2}{x^2 + 7x - 18} - \frac{6x^5}{x^2 - 11x + 18}$$ and analyze its components.
2. **Factor the denominators:**
- Factor $$x^2 + 7x - 18$$:
$$x^2 + 7x - 18 = (x + 9)(x - 2)$$
- Factor $$x^2 - 11x + 18$$:
$$x^2 - 11x + 18 = (x - 9)(x - 2)$$
3. **Rewrite the expression with factored denominators:**
$$\frac{15x^2}{(x + 9)(x - 2)} - \frac{6x^5}{(x - 9)(x - 2)}$$
4. **Find the common denominator:**
The common denominator is $$ (x + 9)(x - 2)(x - 9) $$.
5. **Rewrite each fraction with the common denominator:**
$$\frac{15x^2 (x - 9)}{(x + 9)(x - 2)(x - 9)} - \frac{6x^5 (x + 9)}{(x - 9)(x - 2)(x + 9)}$$
6. **Expand the numerators:**
- First numerator:
$$15x^2 (x - 9) = 15x^3 - 135x^2$$
- Second numerator:
$$6x^5 (x + 9) = 6x^6 + 54x^5$$
7. **Combine the fractions:**
$$\frac{15x^3 - 135x^2 - (6x^6 + 54x^5)}{(x + 9)(x - 2)(x - 9)} = \frac{15x^3 - 135x^2 - 6x^6 - 54x^5}{(x + 9)(x - 2)(x - 9)}$$
8. **Simplify the numerator:**
$$-6x^6 - 54x^5 + 15x^3 - 135x^2$$
9. **Factor out the greatest common factor (GCF) from the numerator:**
GCF is $$-3x^2$$:
$$-3x^2 (2x^4 + 18x^3 - 5x + 45)$$
10. **Final simplified expression:**
$$\frac{-3x^2 (2x^4 + 18x^3 - 5x + 45)}{(x + 9)(x - 2)(x - 9)}$$
**Note:** The function has vertical asymptotes at the roots of the denominators: $$x = -9, 2, 9$$.
This completes the simplification and analysis of the given rational expression.
Rational Expression F2Cd49
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