Solve a system of equations

[ptc-4921095]

Hi, I am having trouble solving this system of equations. I have set up a given block but must be overlooking something. Any help is appreciated. Thanks!

[Werner_E]

1) Its the variable D which throws the error - its undefined. Either define it (or should it be D.r or D.s?) or use it a additional parameter in the function "soln".

2) Even if the solve block would work, the next line will give you the error as DeltaS is unknown. You have set up the solve block as a function, so you will have to call that function and assign the results to appropriate variables.

[AlanStevens]

See attached for how to get it to work (you'll need to check I've made the right assumptions about the D's).

Also, I suggest you turn your definition of deltaH into a function (of Tc and deltaS) as you use it in several different places. I haven't done this in the attached, but it will save you retyping the same thing over and over, which is often a source of error.

Alan