I have three variables (ISP, ch, $n_C$). I have two equations. My aim is to solve a system of two equations to compute the values of ISP and ch according to $n_C$.
My two equations are polynomials of order two. I put the equations in a framabin : https://framabin.org/p/?2ea1412d13d7f562#vh/+dEhivcOqEQAl3RerwPLb4XPAYRB4ehQ+eAL65MM=
I tried the solvers of sage and simpy but it does not work. I tried to use Groebner basis but I failed. I looked at the different questions of sagemath but I am completely lost. Number theory is not at all my background.