1. **State the problem:** Solve the equation $ (x - 5)(x + 4) = (x + 7)(x - 6) $.
2. **Use the distributive property (FOIL) to expand both sides:**
$$ (x - 5)(x + 4) = x^2 + 4x - 5x - 20 = x^2 - x - 20 $$
$$ (x + 7)(x - 6) = x^2 - 6x + 7x - 42 = x^2 + x - 42 $$
3. **Set the expanded expressions equal:**
$$ x^2 - x - 20 = x^2 + x - 42 $$
4. **Subtract $x^2$ from both sides to simplify:**
$$ \cancel{x^2} - x - 20 = \cancel{x^2} + x - 42 $$
$$ -x - 20 = x - 42 $$
5. **Add $x$ to both sides:**
$$ -x + x - 20 = x + x - 42 $$
$$ -20 = 2x - 42 $$
6. **Add 42 to both sides:**
$$ -20 + 42 = 2x - 42 + 42 $$
$$ 22 = 2x $$
7. **Divide both sides by 2:**
$$ \frac{22}{\cancel{2}} = \frac{2x}{\cancel{2}} $$
$$ 11 = x $$
**Final answer:**
$$ x = 11 $$
Solve Quadratic F454C7
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.