đk x khác 1
\(\dfrac{1}{x-1}-\dfrac{2}{3}\left(-\dfrac{9}{20}\right)=\dfrac{5}{2\left(1-x\right)}\)
\(\Leftrightarrow\dfrac{1}{x-1}+\dfrac{3}{10}=-\dfrac{5}{2\left(x-1\right)}\Leftrightarrow\dfrac{10+3\left(x-1\right)+25}{10\left(x-1\right)}=0\Rightarrow32+3x=0\Leftrightarrow x=-\dfrac{32}{3}\)