Pricing Calculator for HP Prime

[akmon]

Use 1 on C and 2 on A as initial value, instead of 0. It solves it. Use this trick when you find that te calculator cannot solve it. Initial values sometimes are very important to find the solution.
Edit: I´ve realised that sometimes using the same values it solves, others don´t, I don´t know why, for example. I insert C=1, A=2, and cannot find solution, however, I press SOLVE again and it solves!. perhaps hp team can explain the behaviour.
PS: I also recommend to solve it using Han´s app SOLVESYS, it solved it at the first attemp.