I need to get a general solution of the following:

ma +5kx = -mgsin(alpha) +11klo

m = mass, k stiffness, g gravity, lo natural length of spring

I think that I need it in the form of:

ab^2 + ab + c = 0

so i can get the auxiliary equation and therefore find the general solution but Im not sure how to rearrange to get in this form

cheers!