\(\dfrac{3}{5x-5}-\dfrac{x+5}{10x-10}=\dfrac{6}{10\left(x-1\right)}-\dfrac{x+5}{10\left(x-1\right)}=\dfrac{6-\left(x+5\right)}{10\left(x-1\right)}\)
\(=\dfrac{-\left(x-1\right)}{10\left(x-1\right)}=-\dfrac{1}{10}\)
\(\dfrac{3}{5x-5}-\dfrac{x+5}{10x-10}\)
= \(\dfrac{3}{5.(x-1)}\) - \(\dfrac{x+5}{2.5.(x-1)}\)
= \(\dfrac{6-x-5}{10.(x-1)}\)
= \(\dfrac{1-x}{10.(x-1)}\)
= \(\dfrac{-1(x-1)}{10(x-1)}\)
= \(\dfrac{-1}{10}\)
\(đk:x\ne1\\ \dfrac{3}{5x-5}-\dfrac{x+5}{10x-10}\\ =\dfrac{3.2}{2.\left(5x-5\right)}-\dfrac{x+5}{10x-10}\\ =\dfrac{6}{10x-10}-\dfrac{x+5}{10x-10}\\ =\dfrac{6-x-5}{10x-10}\\ =\dfrac{1-x}{10x-10}\\ =\dfrac{-\left(x-1\right)}{10\left(x-1\right)}\\ =\dfrac{-1}{10}\)