Equation $\frac {x^2-x-6}{x^2+x -2} - \frac {2x-4}{x-1}$ I am trying to answer the problem as to how to show $\dfrac {x^2-x-6}{x^2+x -2} - \dfrac {2x-4}{x-1} = -1$
I have the key with the answer; the left-hand side is supposed to reduce to $ -1$ and have confirmed this is correct but which steps do I take to reach that answer?

Note that $$\dfrac{x^2 - x - 6}{x^2 + x-2} = \frac{(x-3)(x+2)}{(x+2)(x - 1)} = \frac {x-3}{x-1}$$
Now, we have a common denominator: $$\frac{(x-3)}{(x-1)} - \frac{2x-4}{(x-1)}=$$ $$= \frac{(x-3) - (2x-4)}{(x-1)} = $$  $$ = \dfrac{-x+1}{x-1} = \dfrac{-(x-1)}{x-1} = -1$$
