\[ \left \{x'(t)=-y(t),y'(t)=2 x(t)+2 y(t)\right \} \] ✓ Mathematica : cpu = 0.111034 (sec), leaf count = 52
\[\left \{\left \{x(t)\to c_1 e^t (\cos (t)-\sin (t))-c_2 e^t \sin (t),y(t)\to 2 c_1 e^t \sin (t)+c_2 e^t (\sin (t)+\cos (t))\right \}\right \}\]
✓ Maple : cpu = 0.034 (sec), leaf count = 42
\[ \left \{ \left \{ x \left ( t \right ) ={{\rm e}^{t}} \left ( \cos \left ( t \right ) {\it \_C2}+\sin \left ( t \right ) {\it \_C1} \right ) ,y \left ( t \right ) =-{{\rm e}^{t}} \left ( \cos \left ( t \right ) {\it \_C1}+\cos \left ( t \right ) {\it \_C2}+\sin \left ( t \right ) {\it \_C1}-\sin \left ( t \right ) {\it \_C2} \right ) \right \} \right \} \]