Start by remembering that the square root symbol gives the non-negative root. The equation says that √(x + 0) is 6. To remove the square root, square both sides: x + 0 = 6² = 36. Now isolate x by moving the constant to the other side, so x = 36 - 0 = 36. Always check radical equations: substituting x = 36 makes the expression inside the root equal to 36, and √36 = 6. So the correct answer is 36.