Systems of Differential Equations · Easy problem

The system $\mathbf x'=\begin{pmatrix}-1&1\\4&-1\end{pmatrix}\mathbf x$ has general solution $\mathbf x(t)=c_1e^{t}\begin{pmatrix}1\\2\end{pmatrix}+c_2e^{-3t}\begin{pmatrix}1\\-2\end{pmatrix}$. For the solution with $\mathbf x(0)=\begin{pmatrix}2\\0\end{pmatrix}$, find $x_1(\ln 2)$.