\[ \left \{x'(t)=-3 x(t)+48 y(t)-28 z(t),y'(t)=-4 x(t)+40 y(t)-22 z(t),z'(t)=-6 x(t)+57 y(t)-31 z(t)\right \} \] ✓ Mathematica : cpu = 0.013743 (sec), leaf count = 157
\[\left \{\left \{x(t)\to e^t \left (c_1 \left (3-2 e^{2 t}\right )+2 \left (e^t-1\right ) \left (3 c_2 \left (3 e^t+5\right )-c_3 \left (5 e^t+9\right )\right )\right ),y(t)\to e^t \left (-2 c_1 \left (e^{2 t}-1\right )+c_2 \left (3 e^t+18 e^{2 t}-20\right )-2 c_3 \left (e^t+5 e^{2 t}-6\right )\right ),z(t)\to e^t \left (-3 c_1 \left (e^{2 t}-1\right )+3 c_2 \left (e^t+9 e^{2 t}-10\right )-c_3 \left (2 e^t+15 e^{2 t}-18\right )\right )\right \}\right \}\]
✓ Maple : cpu = 0.063 (sec), leaf count = 66
\[ \left \{ \left \{ x \left ( t \right ) ={{\rm e}^{2\,t}}{\it \_C1}+{\it \_C2}\,{{\rm e}^{t}}+{\it \_C3}\,{{\rm e}^{3\,t}},y \left ( t \right ) ={\frac {{{\rm e}^{2\,t}}{\it \_C1}}{4}}+{\frac {2\,{\it \_C2}\,{{\rm e}^{t}}}{3}}+{\it \_C3}\,{{\rm e}^{3\,t}},z \left ( t \right ) ={\frac {{{\rm e}^{2\,t}}{\it \_C1}}{4}}+{\it \_C2}\,{{\rm e}^{t}}+{\frac {3\,{\it \_C3}\,{{\rm e}^{3\,t}}}{2}} \right \} \right \} \]