Solve coupled 2nd order ODE

Hi guys,

I got two second order equations that look like this with force 'F' time dependent:

I've tried numerous methods to uncouple them but with no success. I also tried using the buil-in functions such 'odeToVectorField' together with 'matlabFunction'.

Any help on how this might be done in MATLAB? Apologies if I'm missing something obvious.

Thanks in advance!