1. **State the problem:** Solve the equation $$\frac{L+2}{L-2} = \frac{-4}{L+2}$$ for $L$.
2. **Formula and rules:** To solve rational equations, we cross-multiply to eliminate denominators, then solve the resulting polynomial equation.
3. **Cross-multiply:**
$$ (L+2)(L+2) = -4(L-2) $$
4. **Expand both sides:**
$$ (L+2)^2 = -4(L-2) $$
$$ L^2 + 4L + 4 = -4L + 8 $$
5. **Bring all terms to one side:**
$$ L^2 + 4L + 4 + 4L - 8 = 0 $$
$$ L^2 + 8L - 4 = 0 $$
6. **Solve quadratic equation:**
Use the quadratic formula $$ L = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} $$ where $a=1$, $b=8$, $c=-4$.
7. **Calculate discriminant:**
$$ \Delta = 8^2 - 4 \times 1 \times (-4) = 64 + 16 = 80 $$
8. **Find roots:**
$$ L = \frac{-8 \pm \sqrt{80}}{2} = \frac{-8 \pm 4\sqrt{5}}{2} $$
9. **Simplify:**
$$ L = -4 \pm 2\sqrt{5} $$
10. **Check for restrictions:**
Denominators cannot be zero, so $L \neq 2$ and $L \neq -2$. Both solutions satisfy this.
**Final answer:**
$$ L = -4 + 2\sqrt{5} \quad \text{or} \quad L = -4 - 2\sqrt{5} $$
Solve Rational 36704F
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.