I am not able even after a whole hour spent on figuring this out to understand the following passage. Please, can you help me out somehow? It is part of the explanation of how a tax affect a monopoly. We start by the assumption that marginal revenue equals margina cost (plus the tax):
$a-2by = c+t$
and we solve for y which leads to:
$y=\frac{a-c-t}{2b}$
Than I don't understand how I can get to this: $\frac{\Delta y}{\Delta t}=- \frac {1}{2b}$
and finally I don't understand why the demand is: $p(y)=a-by$
Thanks for the help in advance!