I don't know what exactly you're trying to solve but I shall give you a method that can be used to solve for all the unknowns C1, C2, J1, and J2.

First I multiply out the fraction and decimals for J1 and J2.

We know a constant value: . To put it into this format, try:

Simply substitute and into this equation. You can now solve for as it's the only variable left.

With you can solve for with

With you can solve for with

With you can solve for with