Solver function Ti-84

There is a problem in one of my assignments for thermodynamics that involves using the solver function on my calculator; however, whenever I enter it in, I receive constant error messages, regardless of the form I enter. I just cant get it right! I was wondering if anyone on here would have any advice on how to enter this equation

[846-323/ln(0.18/0.15)/2(pi)(35)+ln(r3/0.18)/2(pi)(0.10)= 2(pi)(r3)(6)(323-300)+ 2(pi)(r3)(0.20)(5.67 x 10^-8)(323^4-300^4)

The answer is supposed to be 0.394 but i keep getting 592.... any advide would be greatly appreciated, also I tried reducing it before putting it in solver, still cant get it to work