\[ \left \{x'(t)+2 x(t)+y'(t)+y(t)=t+e^{2 t},x'(t)-x(t)+y'(t)+3 y(t)=e^t-1\right \} \] ✓ Mathematica : cpu = 0.245968 (sec), leaf count = 84
\[\left \{\left \{x(t)\to \frac {5}{72} c_1 e^{-7 t/5}+\frac {3 t}{7}-\frac {e^t}{6}+\frac {5 e^{2 t}}{17}-\frac {1}{49},y(t)\to \frac {5}{48} c_1 e^{-7 t/5}+\frac {t}{7}+\frac {e^t}{4}-\frac {e^{2 t}}{17}-\frac {26}{49}\right \}\right \}\]
✓ Maple : cpu = 0.064 (sec), leaf count = 51
\[ \left \{ \left \{ x \left ( t \right ) ={\frac {3\,t}{7}}-{\frac {1}{49}}-{\frac {{{\rm e}^{t}}}{6}}+{\frac {5\,{{\rm e}^{2\,t}}}{17}}+{{\rm e}^{-{\frac {7\,t}{5}}}}{\it \_C1},y \left ( t \right ) =-{\frac {{{\rm e}^{2\,t}}}{17}}+{\frac {t}{7}}-{\frac {26}{49}}+{\frac {{{\rm e}^{t}}}{4}}+{\frac {3\,{\it \_C1}}{2}{{\rm e}^{-{\frac {7\,t}{5}}}}} \right \} \right \} \]