Solve Rational Equation 239Df1
1. **State the problem:** Solve the equation $\frac{32}{a} = a - 4$ for $a$.
2. **Rewrite the equation:** Multiply both sides by $a$ (assuming $a \neq 0$) to eliminate the denominator:
$$32 = a(a - 4)$$
3. **Expand the right side:**
$$32 = a^2 - 4a$$
4. **Bring all terms to one side to form a quadratic equation:**
$$a^2 - 4a - 32 = 0$$
5. **Use the quadratic formula:** For $ax^2 + bx + c = 0$, solutions are
$$a = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
Here, $a=1$, $b=-4$, $c=-32$.
6. **Calculate the discriminant:**
$$\Delta = (-4)^2 - 4 \times 1 \times (-32) = 16 + 128 = 144$$
7. **Find the roots:**
$$a = \frac{4 \pm \sqrt{144}}{2} = \frac{4 \pm 12}{2}$$
8. **Calculate each root:**
- $a = \frac{4 + 12}{2} = \frac{16}{2} = 8$
- $a = \frac{4 - 12}{2} = \frac{-8}{2} = -4$
9. **Check for restrictions:** Since $a$ is in the denominator in the original equation, $a \neq 0$. Both $8$ and $-4$ are valid.
**Final answer:**
$$a = 8 \text{ or } a = -4$$