1. **State the problem:** Solve the equation $$12 \times \frac{120}{n + 5} = 12 \times \frac{120}{n} - 24$$ for $n$.
2. **Write the equation clearly:**
$$12 \cdot \frac{120}{n + 5} = 12 \cdot \frac{120}{n} - 24$$
3. **Simplify the terms:**
$$\frac{1440}{n + 5} = \frac{1440}{n} - 24$$
4. **Isolate the fractions:**
Move all terms to one side:
$$\frac{1440}{n + 5} - \frac{1440}{n} = -24$$
5. **Find common denominator and combine:**
$$\frac{1440n - 1440(n + 5)}{n(n + 5)} = -24$$
6. **Simplify numerator:**
$$1440n - 1440n - 7200 = -7200$$
So,
$$\frac{-7200}{n(n + 5)} = -24$$
7. **Multiply both sides by $n(n + 5)$:**
$$-7200 = -24 \times n(n + 5)$$
8. **Divide both sides by -24:**
$$\cancel{-7200} \div \cancel{-24} = n(n + 5)$$
$$300 = n^2 + 5n$$
9. **Rewrite as quadratic equation:**
$$n^2 + 5n - 300 = 0$$
10. **Solve quadratic using the quadratic formula:**
$$n = \frac{-5 \pm \sqrt{5^2 - 4 \times 1 \times (-300)}}{2 \times 1} = \frac{-5 \pm \sqrt{25 + 1200}}{2} = \frac{-5 \pm \sqrt{1225}}{2}$$
11. **Calculate the square root:**
$$\sqrt{1225} = 35$$
12. **Find the two solutions:**
$$n = \frac{-5 + 35}{2} = \frac{30}{2} = 15$$
$$n = \frac{-5 - 35}{2} = \frac{-40}{2} = -20$$
13. **Check for restrictions:**
Denominators $n$ and $n+5$ cannot be zero, so $n \neq 0$ and $n \neq -5$. Both 15 and -20 are valid.
**Final answer:**
$$n = 15 \text{ or } n = -20$$
Solve Rational Equation D9E6Ef
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