1. **State the problem:** Solve the equation $$a^3 + a^2 = 42a$$ for all values of $a$.
2. **Rewrite the equation:** Move all terms to one side to set the equation equal to zero:
$$a^3 + a^2 - 42a = 0$$
3. **Factor the equation:** Factor out the common factor $a$:
$$a(a^2 + a - 42) = 0$$
4. **Apply the zero product property:** For the product to be zero, either
$$a = 0$$
or
$$a^2 + a - 42 = 0$$
5. **Solve the quadratic equation:** Use the quadratic formula for
$$a^2 + a - 42 = 0$$
where $a=1$, $b=1$, and $c=-42$:
$$a = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{-1 \pm \sqrt{1^2 - 4 \times 1 \times (-42)}}{2 \times 1} = \frac{-1 \pm \sqrt{1 + 168}}{2} = \frac{-1 \pm \sqrt{169}}{2}$$
6. **Simplify the square root:**
$$\sqrt{169} = 13$$
7. **Find the two roots:**
$$a = \frac{-1 + 13}{2} = \frac{12}{2} = 6$$
$$a = \frac{-1 - 13}{2} = \frac{-14}{2} = -7$$
8. **List all solutions:**
$$a = 0, 6, -7$$
**Final answer:** The solutions to the equation are $0, 6, -7$.
Solve Cubic 6Aac98
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