Matrix representation for modal analysis

Good evening,

the problem is the following:

I have a system of two coupled differential equations, and i have to build the matrix representation of this system. The two equations are similar with respect to their structures:

(mass coefficient) x (d^2(y)/dt^2) + (damping coefficient) x (d(y)/dt) + (elastic coefficient) x (y) = known term
(mass coefficient) x (d^2(y)/dt^2) + (damping coefficient) x (d(y)/dt) + (elastic coefficient) x (y) = known term

I have to put in a matrix all the mass coefficients, in an other matrix all the damping coefficients, and in other matrices the elastic coefficients, the known terms, the (d^2(y)/dt^2) terms, (d(y)/dt) terms, (y) terms.

In this way i can handle one single equation in matrix form.

What is the command to do that? What is the structure of the script?

Thank you very much,

Alessio