1. **Problem statement:** Solve the equation $$(x - 1)^3 + 3(x + 1)^2 + x(x - 3)(x + 3) = 2x^3 + 2.$$
2. **Recall formulas and rules:**
- Expand powers and products carefully.
- Use the identity $x^2 - 9 = (x - 3)(x + 3)$.
- Combine like terms and simplify both sides.
3. **Expand each term:**
- $(x - 1)^3 = x^3 - 3x^2 + 3x - 1$
- $(x + 1)^2 = x^2 + 2x + 1$ so $3(x + 1)^2 = 3x^2 + 6x + 3$
- $x(x - 3)(x + 3) = x(x^2 - 9) = x^3 - 9x$
4. **Sum left side:**
$$x^3 - 3x^2 + 3x - 1 + 3x^2 + 6x + 3 + x^3 - 9x = (x^3 + x^3) + (-3x^2 + 3x^2) + (3x + 6x - 9x) + (-1 + 3)$$
$$= 2x^3 + 0 + 0 + 2 = 2x^3 + 2$$
5. **Right side is already:**
$$2x^3 + 2$$
6. **Set equation:**
$$2x^3 + 2 = 2x^3 + 2$$
7. **Conclusion:**
Both sides are equal for all real $x$. Therefore, the equation holds for every real number.
**Final answer:** All real numbers $x$ satisfy the equation.
Cubic Equation B88D2E
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