\[ \left \{x'(t)=-y(t),y'(t)=2 x(t)+2 y(t)\right \} \] ✓ Mathematica : cpu = 0.011661 (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 = 0.037 (sec), leaf count = 39
\[ \left \{ \left \{ x \left ( t \right ) ={{\rm e}^{t}} \left ( \sin \left ( t \right ) {\it \_C1}+\cos \left ( t \right ) {\it \_C2} \right ) ,y \left ( t \right ) =- \left ( \left ( {\it \_C1}+{\it \_C2} \right ) \cos \left ( t \right ) +\sin \left ( t \right ) \left ( {\it \_C1}-{\it \_C2} \right ) \right ) {{\rm e}^{t}} \right \} \right \} \]