a) Ta có: \(\dfrac{x-8}{2}-\dfrac{x}{10}=4\)
\(\Leftrightarrow\dfrac{5\left(x-8\right)}{10}-\dfrac{x}{10}=\dfrac{40}{10}\)
\(\Leftrightarrow5x-40-x=40\)
\(\Leftrightarrow4x=80\)
hay x=20
Vậy: S={20}
b)
ĐKXĐ: \(x\notin\left\{0;2\right\}\)
Ta có: \(\dfrac{x-1}{x}+\dfrac{2x-2}{x\left(x-2\right)}=0\)
\(\Leftrightarrow\dfrac{\left(x-1\right)\left(x-2\right)}{x\left(x-2\right)}+\dfrac{2x-2}{x\left(x-2\right)}=0\)
Suy ra: \(x^2-3x+2+2x-2=0\)
\(\Leftrightarrow x^2-x=0\)
\(\Leftrightarrow x\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(loại\right)\\x=1\left(nhận\right)\end{matrix}\right.\)
Vậy: S={1}
