\[ \left \{4 x'(t)+44 x(t)+9 y'(t)+49 y(t)=t,3 x'(t)+34 x(t)+7 y'(t)+38 y(t)=e^t\right \} \] ✓ Mathematica : cpu = 0.0448097 (sec), leaf count = 322
\[\left \{\left \{x(t)\to \frac {1}{5} c_1 e^{-6 t} \left (4 e^{5 t}+1\right )-\frac {1}{5} c_2 e^{-6 t} \left (e^{5 t}-1\right )-\frac {1}{5} e^{-6 t} \left (e^{5 t}-1\right ) \left (\frac {16}{5} e^{6 t} \left (\frac {t}{6}-\frac {1}{36}\right )+4 e^{2 t}-\frac {4 e^{7 t}}{7}-\frac {31}{5} e^t (t-1)\right )+\frac {1}{25} e^{-6 t} \left (4 e^{5 t}+1\right ) \left (e^{6 t} \left (\frac {2 t}{3}-\frac {1}{9}\right )-20 e^{2 t}-\frac {5 e^{7 t}}{7}+e^t (31 t-31)\right ),y(t)\to -\frac {4}{5} c_1 e^{-6 t} \left (e^{5 t}-1\right )+\frac {1}{5} c_2 e^{-6 t} \left (e^{5 t}+4\right )+\frac {1}{5} e^{-6 t} \left (e^{5 t}+4\right ) \left (\frac {16}{5} e^{6 t} \left (\frac {t}{6}-\frac {1}{36}\right )+4 e^{2 t}-\frac {4 e^{7 t}}{7}-\frac {31}{5} e^t (t-1)\right )-\frac {4}{25} e^{-6 t} \left (e^{5 t}-1\right ) \left (e^{6 t} \left (\frac {2 t}{3}-\frac {1}{9}\right )-20 e^{2 t}-\frac {5 e^{7 t}}{7}+e^t (31 t-31)\right )\right \}\right \}\]
✓ Maple : cpu = 0.063 (sec), leaf count = 52
\[ \left \{ \left \{ x \left ( t \right ) ={\it \_C2}\,{{\rm e}^{-t}}+{{\rm e}^{-6\,t}}{\it \_C1}-{\frac {56}{9}}+{\frac {19\,t}{3}}-{\frac {29\,{{\rm e}^{t}}}{7}},y \left ( t \right ) =-{\it \_C2}\,{{\rm e}^{-t}}+4\,{{\rm e}^{-6\,t}}{\it \_C1}+{\frac {55}{9}}+{\frac {24\,{{\rm e}^{t}}}{7}}-{\frac {17\,t}{3}} \right \} \right \} \]