1. **State the problem:** Solve the rational equation $$\frac{7}{x + 2} + \frac{3x + 5}{x - 2} = \frac{2x + 7}{x - 2}$$.
2. **Identify the denominators:** The denominators are $x+2$ and $x-2$. To eliminate the fractions, multiply both sides of the equation by the least common denominator (LCD), which is $(x+2)(x-2)$.
3. **Multiply both sides by the LCD:**
$$ (x+2)(x-2) \times \left( \frac{7}{x + 2} + \frac{3x + 5}{x - 2} \right) = (x+2)(x-2) \times \frac{2x + 7}{x - 2} $$
4. **Distribute and simplify:**
$$ 7 \cancel{(x+2)} \frac{(x-2)}{\cancel{(x+2)}} + (3x + 5) \cancel{(x-2)} \frac{(x+2)}{\cancel{(x-2)}} = (2x + 7) \cancel{(x-2)} \frac{(x+2)}{\cancel{(x-2)}} $$
This simplifies to:
$$ 7(x-2) + (3x + 5)(x+2) = (2x + 7)(x+2) $$
5. **Expand each term:**
$$ 7x - 14 + (3x^2 + 6x + 5x + 10) = 2x^2 + 4x + 7x + 14 $$
Simplify inside the parentheses:
$$ 7x - 14 + 3x^2 + 11x + 10 = 2x^2 + 11x + 14 $$
6. **Combine like terms on the left:**
$$ 3x^2 + (7x + 11x) + (-14 + 10) = 2x^2 + 11x + 14 $$
$$ 3x^2 + 18x - 4 = 2x^2 + 11x + 14 $$
7. **Bring all terms to one side to set equation to zero:**
$$ 3x^2 + 18x - 4 - 2x^2 - 11x - 14 = 0 $$
Simplify:
$$ (3x^2 - 2x^2) + (18x - 11x) + (-4 - 14) = 0 $$
$$ x^2 + 7x - 18 = 0 $$
8. **Solve the quadratic equation:**
Use the quadratic formula:
$$ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} $$
where $a=1$, $b=7$, $c=-18$.
Calculate the discriminant:
$$ \Delta = 7^2 - 4 \times 1 \times (-18) = 49 + 72 = 121 $$
Calculate the roots:
$$ x = \frac{-7 \pm \sqrt{121}}{2} = \frac{-7 \pm 11}{2} $$
9. **Find the two solutions:**
- For $+$:
$$ x = \frac{-7 + 11}{2} = \frac{4}{2} = 2 $$
- For $-$:
$$ x = \frac{-7 - 11}{2} = \frac{-18}{2} = -9 $$
10. **Check for restrictions:** The original denominators are $x+2$ and $x-2$, so $x \neq -2$ and $x \neq 2$ to avoid division by zero.
Since $x=2$ is not allowed, discard it.
11. **Final solution:**
$$ \boxed{x = -9} $$
Rational Equation 540635
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