Start by remembering that the square root symbol gives the non-negative root. The equation says that √(x + 1) is 5. To remove the square root, square both sides: x + 1 = 5² = 25. Now isolate x by moving the constant to the other side, so x = 25 - 1 = 24. Always check radical equations: substituting x = 24 makes the expression inside the root equal to 25, and √25 = 5. So the correct answer is 24.