Answer
$-\frac{3}{x-1}$
Work Step by Step
By inspection, we see that there is a common denominator of $(x-1)$. Therefore, we obtain:
$\frac{3}{x-1}-\frac{6}{x-1}$
=$\frac{3-(6)}{x-1}$
=$\frac{3-6}{x-1}$
=$\frac{-3}{x-1}$
=$-\frac{3}{x-1}$