Hey, everybody. I have this expression
expr = (A (n1 - n1^2 + n2 + 2 n1 n2 - n2^2) +
c ((-1 + n1) n1 - (1 + 2 n1) n2 + n2^2) +
n1 (1 - n1 + n2) \[Gamma]1 + (1 + n1 - n2) n2 \[Gamma]2)/(B (1 + n1 +
n2))
I wish to simplify it, with the assumption n1=n2 and n1 + n2 = N. However, I want to keep the distinction between the two variables.
I should find
(N (A - c + (n2 \[Gamma]2 * n1 \[Gamma]1) / N)/(B (1 + N))
However I don't know how to enter the assumptions, because n1 = n2 replaces the variable.
Thanks in advance if you have an answer