Complex Solutions

1. What are the solutions of x^{2} + 9 = 0?

2. What are the solutions of (x + 1)^{2} + 4 = 0?

3. What are the solutions of x^{2} – 2x + 10 = 0?

4. What are the solutions of x^{3} + 25x = 0?

5. What are the solutions of (x – 1)^{3} + 36(x – 1) = 0?