a: 2x-1=0
=>2x=1
=>\(x=\dfrac{1}{2}\)
b: ĐKXĐ: \(x\notin\left\{1;-1\right\}\)
\(\dfrac{x+1}{x-1}-\dfrac{1}{x+1}=\dfrac{x^2+2}{x^2-1}\)
=>\(\dfrac{x+1}{x-1}-\dfrac{1}{x+1}=\dfrac{x^2+2}{\left(x-1\right)\left(x+1\right)}\)
=>\(\dfrac{\left(x+1\right)^2-x+1}{\left(x-1\right)\left(x+1\right)}=\dfrac{x^2+2}{\left(x-1\right)\left(x+1\right)}\)
=>\(x^2+2x+1-x+1=x^2+2\)
=>x+2=2
=>x=0(nhận)