Not a quantified system of equations and inequalities

[patrickrichardsen]

Can someone please help me why I’m recieving this error. I am very new to Mathematica (just started yesterday), but I can do the calculation by hand why can’t mathematica? I’m trying to solve the two equations R1 and R2 for P1 and P2. Maybe I’m just being dumb lol. Here is a screen dump:

[rohitnamjoshi]

Please post code that can be copied/pasted and evaluated to reproduce the problem.

Check the documentation for Solve. There are too many { }. Perhaps you mean this?

Solve[{R1 == (A + b c + k P2)/(2 b), R2 == m P1}, {P1, P2}]
(* {{P1 -> R2/m, P2 -> (-A - b c + 2 b R1)/k}} *)

[patrickrichardsen]

Hi, i kinda figured it out. I think my code is pretty bad though. I will attach my Notebook, maybe you can come with some helpful tips. I further want to plug in values for my constants in order to graph my spesific problem, but do not know how to do this without ruining my general solution for the model.

Open in Wolfram Cloud ↗

[rohitnamjoshi]

Something like this with some specific values for A, c1, b, k and varying m. The specific values are scoped to the With.

With[{vals = {A -> 1, c1 -> 2, b -> 1, k -> 1}},
 eqns = {P1, P2} /. First@Eq /. vals;
 Plot[eqns, {m, 0, 1}, PlotLegends -> "Expressions"]]