I want to draw a direction field and solve this system of differential equations using Mathematica, but I've been researching, and I can't find a way to do this:

$$\mathbf{x'} = \begin{pmatrix} 1 & 1\\ 4 & -2 \end{pmatrix} \mathbf{x}$$

Note: I'm still a newbie to Mathematica, so please be patient with me. Thanks!