Rút gọn a đã x khác +-1
\(\frac{x.\left(x-1\right)+\left(x+1\right)+2x}{x^2-1}.\frac{6}{\left(x+1\right)}=\frac{6.\left(x+1\right)^2}{\left(x^2-1\right)\left(x+1\right)}=\frac{6}{x-1}\)
A=x=> 6=x.(x-1)=> x^2-x-6=0
\(x=\frac{1+-5}{2}=\orbr{\begin{cases}x=-1Loia\\3\end{cases}}\)
KL x=3