`((2(m-1))/m)^2 -2=6` ($m\neq$0)
`<=> ((2(m-1))/m)^2 =8`
`<=> 4m^2-8m+4=8m^2`
`<=> m^2-2m+1= 2m^2`
`<=> m^2-2m^2-2m+1=0`
`<=> -m^2-2m+1=0`
`<=> m^2+2m-1=0`
`<=> (m^2+2m+1)-2=0`
`<=> (m+1)^2=2`
`<=>` \(\left[ \begin{array}{l}m+1=\sqrt2\\m+1=-\sqrt2\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}m=\sqrt2-1\\m=-\sqrt2-1\end{array} \right.\) `(tm)`
Vậy pt có nghiệm \(\left[ \begin{array}{l}m=\sqrt2-1\\m=-\sqrt2-1\end{array} \right.\)
