Subjects algebra

Solve Cube 891195

Step-by-step solutions with LaTeX - clean, fast, and student-friendly.

Use the AI math solver

Question: Solve $(v-2)^3 + 64 = 0$ where $v$ is a real number. Write your answer in simplified radical form. (If there is more than one solution, separate them with commas.) $v = $
1. **State the problem:** Solve the equation $$ (v-2)^3 + 64 = 0 $$ for real $v$. 2. **Rewrite the equation:** Recognize that $$64 = 4^3$$, so the equation becomes $$ (v-2)^3 + 4^3 = 0 $$. 3. **Use the sum of cubes formula:** Recall that $$a^3 + b^3 = (a+b)(a^2 - ab + b^2)$$. 4. **Apply the formula:** Let $$a = v-2$$ and $$b = 4$$, then $$ (v-2)^3 + 4^3 = (v-2 + 4)((v-2)^2 - (v-2)(4) + 4^2) = 0 $$. 5. **Simplify the factors:** - First factor: $$v - 2 + 4 = v + 2$$ - Second factor: $$ (v-2)^2 - 4(v-2) + 16 = (v^2 - 4v + 4) - 4v + 8 + 16 = v^2 - 8v + 28 $$ 6. **Set each factor equal to zero:** - $$v + 2 = 0 \\ \Rightarrow v = -2$$ - $$v^2 - 8v + 28 = 0$$ 7. **Solve the quadratic:** Use the quadratic formula: $$ v = \frac{8 \pm \sqrt{(-8)^2 - 4 \cdot 1 \cdot 28}}{2} = \frac{8 \pm \sqrt{64 - 112}}{2} = \frac{8 \pm \sqrt{-48}}{2} $$ 8. **Simplify the discriminant:** $$ \sqrt{-48} = \sqrt{-1 \cdot 16 \cdot 3} = 4i\sqrt{3} $$ 9. **Write the complex solutions:** $$ v = \frac{8 \pm 4i\sqrt{3}}{2} = 4 \pm 2i\sqrt{3} $$ 10. **Identify real solutions:** Only $$v = -2$$ is real. **Final answer:** $$ v = -2 $$