For a quadratic equation ax^2 + bx + c = 0, you do not need to find both roots when only the sum is asked. Use Vieta's formula: sum of roots = -b/a. In x^2 - 5x - 24 = 0, a = 1 and b = -5. So the sum is -(-5)/1 = 5. Therefore, the correct answer is 5.