1. **State the problem:** Solve the equation $3x^2 + 3x^2 = 24$ for $x$. 2. **Combine like terms:** Since both terms are $3x^2$, add them: $$3x^2 + 3x^2 = 6x^2$$ 3. **Rewrite the equation:** $$6x^2 = 24$$ 4. **Isolate $x^2$:** Divide both sides by 6: $$x^2 = \frac{24}{6} = 4$$ 5. **Solve for $x$:** Take the square root of both sides: $$x = \pm \sqrt{4} = \pm 2$$ 6. **Final answer:** $$x = 2 \text{ or } x = -2$$