[tex]\frac{ (\frac{2}{x} -1)}{ (\frac{1}{x} -1)}= \frac{( \frac{2-x}{x})}{( \frac{1-x}{x})} = \frac{2-x}{1-x} [/tex]. Now the answers on your paper do not have this choice, but if you think about it, (2-x)=-1(x-2) and (1-x)=-1(x-1). This means that when you have (2-x)/(1-x), this also equals to (x-2)/(x-1), since the -1's cancel out. So, the answer is D.
I hope this was helpful!
