1. **State the problem:** Explain how we got the term $9n$ in the equation. 2. **Recall the step before:** We had the equation $n - \frac{1}{n} = 9$. 3. **Multiply both sides by $n$:** To eliminate the fraction, multiply every term by $n$: $$n \times n - n \times \frac{1}{n} = 9 \times n$$ 4. **Simplify each term:** - $n \times n = n^2$ - $n \times \frac{1}{n} = 1$ - $9 \times n = 9n$ 5. **Resulting equation:** $$n^2 - 1 = 9n$$ 6. **Summary:** The $9n$ comes from multiplying the right side $9$ by $n$ to clear the denominator on the left side.