# Express the general solution?

Express the general solution of x'=(3, 4, -2, -1)x in terms of real-valued functions.

This is 2x2 matrix, 3 and 4 on the left, -2 and -1 on the right. I know that the eigenvalues are 1+2i, 1-2i. And a=1, b=1+i for the first eigenvalue. a=1, b=1-i for the second eigenvalue. But how do I get the answer?