Question: If the quadratic equation x^2 + 4x + c = 0 has one root equal to -2, what is the value of c?
Options:
Correct Answer: 0
Solution:
If one root is -2, then substituting x = -2 gives: (-2)^2 + 4(-2) + c = 0 => 4 - 8 + c = 0 => c = 4.