\[ \left \{x'(t)=-y(t),y'(t)=2 x(t)+2 y(t)\right \} \] ✓ Mathematica : cpu = 0.0752874 (sec), leaf count = 46
\[\left \{\left \{x(t)\to e^t \left (c_1 \cos (t)-\left (c_1+c_2\right ) \sin (t)\right ),y(t)\to e^t \left (2 c_1 \sin (t)+c_2 (\sin (t)+\cos (t))\right )\right \}\right \}\]
✓ Maple : cpu = 0.04 (sec), leaf count = 39
\[ \left \{ \left \{ x \left ( t \right ) ={{\rm e}^{t}} \left ( \sin \left ( t \right ) {\it \_C1}+\cos \left ( t \right ) {\it \_C2} \right ) ,y \left ( t \right ) =-{{\rm e}^{t}} \left ( \left ( {\it \_C1}+{\it \_C2} \right ) \cos \left ( t \right ) +\sin \left ( t \right ) \left ( {\it \_C1}-{\it \_C2} \right ) \right ) \right \} \right \} \]