Algebra equation, is this possible to solve ? Where to start?

Hi,

I would like to know if this is possible to solve ? Is there enough data ?

C1 - C2 = 750 euros

J1 = C1 * 8/12 * 0,06

J2 = C2 * 6/12 * 0,04

J1 = 2,5 * J2

What I've done so far was,

J1 = 2,5(C2 * 6/12 * 0,04)

J1 = 2,5( 0,24C2/12 )

J1 = 0,6C2/12

12J1 = 0,6C2

C2 = 12J1/0,6

Now I'm thinking about getting C1, by doing J1 = C1 * 8/12 * 0,06 and so on. But I dont know if this is the right way to work it.

Thanks,

any sugestion is appreciated!