Solve the IVP by a CAS, giving a general solution and the

Solve the IVP by a CAS, giving a general solution and the particular solution and its graph.

y"' + 7.5y" + 14.25y' - 9.125y = 0, y(0) = 10.05, y' (0) = -54.975, y" (0) = 257.5125