#### bobbym wrote:

Hi;

When I divide the first term by it, it becomes simply (Pi/P).

When I divide the second term by it, it becomes: -((Pi-w)n)/P

You mean multiply instead of divide, and you are correct up to there.

Yes, sorry again. I do mean multiply.

What have I done wrong after? I really do not know what is going on, I have spent hours here.

Alternatively I try multiplying the P across from this step: So (Pi/P) -((Pi-w)n)/P = 0

To get Pi - (Pi-w)/n = 0. Then it leads to the same thing, as I divide by P later to try to get the Pi/P expression. These two ways seem equivalent.