I have the following question in my text book:
Express as a single fraction
$ \frac{3}{x-4} - \frac{2}{(x-4)^2} $
The answer the book gives is this:
$ \frac{3x-14}{(x-4)^2} $
I understand how they get to this through these steps:
$ \frac{3(x-4)-2}{(x-4)^2} = \frac{3x-12-2}{(x-4)^2} $
My question is why can you not cancel the $ (x-4) $ instead like this:
$ \frac{3(x-4)-2}{(x-4)^2} = \frac{3-2}{(x-4)} = \frac{1}{(x-4)} $