$\frac{x}{\frac{1}{x}-1}+\frac{x}{x-1}$
A) -1
B) -x
C) x
D) x+1
E) -x+1
$\frac{-x^2}{x-1}+\frac{x}{x-1}=\frac{-x.(x-1)}{x-1}=-x$