\[ \left \{4 x'(t)+11 x(t)+9 y'(t)+31 y(t)=e^t,3 x'(t)+8 x(t)+7 y'(t)+24 y(t)=e^{2 t}\right \} \] ✓ Mathematica : cpu = 0.0597601 (sec), leaf count = 81
\[\left \{\left \{x(t)\to \frac {1}{900} e^{-4 t} \left (-900 \left (c_1 (t-1)+c_2 t\right )+1116 e^{5 t}-1225 e^{6 t}\right ),y(t)\to \frac {1}{900} e^{-4 t} \left (900 \left (\left (c_1+c_2\right ) t+c_2\right )-396 e^{5 t}+475 e^{6 t}\right )\right \}\right \}\]
✓ Maple : cpu = 0.068 (sec), leaf count = 65
\[ \left \{ \left \{ x \left ( t \right ) ={{\rm e}^{-4\,t}}{\it \_C2}+{{\rm e}^{-4\,t}}t{\it \_C1}-{\frac {49\,{{\rm e}^{2\,t}}}{36}}+{\frac {31\,{{\rm e}^{t}}}{25}},y \left ( t \right ) ={\frac {19\,{{\rm e}^{2\,t}}}{36}}-{{\rm e}^{-4\,t}}{\it \_C2}-{{\rm e}^{-4\,t}}t{\it \_C1}-{{\rm e}^{-4\,t}}{\it \_C1}-{\frac {11\,{{\rm e}^{t}}}{25}} \right \} \right \} \]