\[ \left \{x'(t)=-y(t),y'(t)=2 x(t)+2 y(t)\right \} \] ✓ Mathematica : cpu = 0.0110795 (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 = 0.045 (sec), leaf count = 39
\[\{x \relax (t ) = {\mathrm e}^{t} \left (c_{1} \sin \relax (t )+c_{2} \cos \relax (t )\right ), y \relax (t ) = -\left (\left (c_{1}+c_{2}\right ) \cos \relax (t )+\sin \relax (t ) \left (c_{1}-c_{2}\right )\right ) {\mathrm e}^{t}\}\]