I am having trouble with the following problem:
The equation $ax^2 + bx + c = 0$ has real coefficients and one solution $x_1 = 2 + i$. What can be said about the other solution $x_2$?
(a) $x_2 = x_1$
(b) $x_2$ is a real number
(c) $x_2 = 2-i$
(d) none of the above
I have tried using the fact that complex roots of a quadratic equation always come in conjugate pairs, but I am not sure how to proceed from there. I am wondering if there is a specific formula or method that can be used to find the other solution.
Any help or guidance would be greatly appreciated. Thank you in advance!