\(\frac{x-1}{2}=\frac{x}{4}\)
\(\Leftrightarrow\)\(\frac{2\left(x-1\right)}{4}=\frac{x}{4}\)
\(\Leftrightarrow\)\(2\left(x-1\right)=x\)
\(\Leftrightarrow\)\(2x-2=x\)
\(\Leftrightarrow\)\(2x-x=2\)
\(\Leftrightarrow\)\(x=2\)
Vậy....
\(\frac{x+1}{x-1}=\frac{1}{2}\)
\(\Leftrightarrow\)\(2\left(x+1\right)=x-1\)
\(\Leftrightarrow\)\(2x+2=x-1\)
\(\Leftrightarrow\)\(2x-x=-1-2\)
\(\Leftrightarrow\)\(x=-3\)
Vậy....