\[ \left \{x'(t)+3 x(t)-y(t)=e^{2 t},x(t)+y'(t)+5 y(t)=e^t\right \} \] ✓ Mathematica : cpu = 0.0900776 (sec), leaf count = 162
\[\left \{\left \{x(t)\to -e^t (t+1) \left (\frac {t}{5}+\frac {1}{36} e^t (6 t-7)-\frac {1}{25}\right )+e^t t \left (\frac {t}{5}+\frac {1}{36} e^t (6 t-1)+\frac {4}{25}\right )+c_1 e^{-4 t} (t+1)+c_2 e^{-4 t} t,y(t)\to e^t t \left (\frac {t}{5}+\frac {1}{36} e^t (6 t-7)-\frac {1}{25}\right )-e^t (t-1) \left (\frac {t}{5}+\frac {1}{36} e^t (6 t-1)+\frac {4}{25}\right )-c_1 e^{-4 t} t-c_2 e^{-4 t} (t-1)\right \}\right \}\] ✓ Maple : cpu = 0.095 (sec), leaf count = 64
\[\left \{\left \{x \left (t \right ) = c_{1} t \,{\mathrm e}^{-4 t}+c_{2} {\mathrm e}^{-4 t}+\frac {{\mathrm e}^{t}}{25}+\frac {7 \,{\mathrm e}^{2 t}}{36}, y \left (t \right ) = -c_{1} t \,{\mathrm e}^{-4 t}+c_{1} {\mathrm e}^{-4 t}-c_{2} {\mathrm e}^{-4 t}+\frac {4 \,{\mathrm e}^{t}}{25}-\frac {{\mathrm e}^{2 t}}{36}\right \}\right \}\]