\[ \left \{4 x'(t)+44 x(t)+9 y'(t)+49 y(t)=t,3 x'(t)+34 x(t)+7 y'(t)+38 y(t)=e^t\right \} \] ✓ Mathematica : cpu = 0.0499636 (sec), leaf count = 104
\[\left \{\left \{x(t)\to \frac {1}{5} \left (4 c_1-c_2\right ) e^{-t}+\frac {1}{5} \left (c_1+c_2\right ) e^{-6 t}+\frac {1}{9} (57 t-56)-\frac {29 e^t}{7},y(t)\to \frac {1}{5} \left (c_2-4 c_1\right ) e^{-t}+\frac {4}{5} \left (c_1+c_2\right ) e^{-6 t}+\frac {1}{9} (55-51 t)+\frac {24 e^t}{7}\right \}\right \}\]
✓ Maple : cpu = 0.06 (sec), leaf count = 52
\[ \left \{ \left \{ x \left ( t \right ) ={{\rm e}^{-t}}{\it \_C2}+{{\rm e}^{-6\,t}}{\it \_C1}-{\frac {29\,{{\rm e}^{t}}}{7}}+{\frac {19\,t}{3}}-{\frac {56}{9}},y \left ( t \right ) =-{{\rm e}^{-t}}{\it \_C2}+4\,{{\rm e}^{-6\,t}}{\it \_C1}+{\frac {24\,{{\rm e}^{t}}}{7}}+{\frac {55}{9}}-{\frac {17\,t}{3}} \right \} \right \} \]