\[ \left \{x'(t)=-3 x(t)+48 y(t)-28 z(t),y'(t)=-4 x(t)+40 y(t)-22 z(t),z'(t)=-6 x(t)+57 y(t)-31 z(t)\right \} \] ✓ Mathematica : cpu = 0.0096629 (sec), leaf count = 179
DSolve[{Derivative[1][x][t] == -3*x[t] + 48*y[t] - 28*z[t], Derivative[1][y][t] == -4*x[t] + 40*y[t] - 22*z[t], Derivative[1][z][t] == -6*x[t] + 57*y[t] - 31*z[t]},{x[t], y[t], z[t]},t]
\[\left \{\left \{x(t)\to c_1 \left (-e^t\right ) \left (2 e^{2 t}-3\right )+6 c_2 e^t \left (2 e^t+3 e^{2 t}-5\right )-2 c_3 e^t \left (4 e^t+5 e^{2 t}-9\right ),y(t)\to -2 c_1 e^t \left (e^{2 t}-1\right )+c_2 e^t \left (3 e^t+18 e^{2 t}-20\right )-2 c_3 e^t \left (e^t+5 e^{2 t}-6\right ),z(t)\to -3 c_1 e^t \left (e^{2 t}-1\right )+3 c_2 e^t \left (e^t+9 e^{2 t}-10\right )-c_3 e^t \left (2 e^t+15 e^{2 t}-18\right )\right \}\right \}\] ✓ Maple : cpu = 0.071 (sec), leaf count = 66
dsolve({diff(x(t),t) = -3*x(t)+48*y(t)-28*z(t), diff(y(t),t) = -4*x(t)+40*y(t)-22*z(t), diff(z(t),t) = -6*x(t)+57*y(t)-31*z(t)})
\[\left \{x \left (t \right ) = c_{1} {\mathrm e}^{2 t}+c_{2} {\mathrm e}^{t}+c_{3} {\mathrm e}^{3 t}, y \left (t \right ) = \frac {c_{1} {\mathrm e}^{2 t}}{4}+\frac {2 c_{2} {\mathrm e}^{t}}{3}+c_{3} {\mathrm e}^{3 t}, z \left (t \right ) = \frac {c_{1} {\mathrm e}^{2 t}}{4}+c_{2} {\mathrm e}^{t}+\frac {3 c_{3} {\mathrm e}^{3 t}}{2}\right \}\]