Chapter 9 - Quadratic Functions and Equations - 9-3 Solving Quadratic Equations - Practice and Problem-Solving Exercises - Page 551: 12

No solution

First, we have to subtract 4 on each side of the problem: $x^2 + 4 = 0$ - 4 -4 So we then get $x^2 = -4$. Now we must square root on both sides, but it is impossible to square root -4, so our answer would be no solution.