How can i solve this equation and make this plot?

Hello everyone, can anyone help me how to solve this equations and make this plot? i try to solve the equations of transient motions of differential equations. Here is the equations M(d2Delta/dt2)+[C1+C2(dtetha/dt)](dDelta/dt)+[K1+K2(d2tetha/dt2)]delta=((dtetha/dt)^2)F1(tehta)+(d2tetha/dt2)F2(tehta). tetha is function of time (example 500t) and M,C1,C2,K1,K2 is a matrix n x n. and for F1,F2 is a matrix by n x 1 and functions of tetha. i don't understand how to solve this equations and my goal is how to plot like this.

 i read my literature "Rotordynamics prediction in engineering" by lalanne but i still don't understand how to solve this equations.
first is tehta isn't functions of time but now tetha is function of time. thank you for your response.