`x^2-2016x-2017=0`
`⇔x^2+x-2017x-2017=0`
`⇔x(x+1)-2017(x+1)=0`
`⇔(x+1)(x-2017)=0`
\(\left[ \begin{array}{l}x+1=0\\x-2017=0\end{array} \right.\)
\(\left[ \begin{array}{l}x=-1\\x=2017\end{array} \right.\)
`x(x-1)(x+1)(x+2)=24`
`⇔(x-1)(x+2)x(x+1)=24`
`⇔(x^2+x-2)(x^2+x)=24`
đặt` t=x^2+x-1`
`⇒(t-1)(t+1)=24`
`⇒t^2-1=24`
`⇒t^2=25`
`⇒(x^2+x-1)^2=25`
$\left \{ {{x^2+x-1=5} \atop {x^2+x-1=-5}} \right.$
$\left \{ {{x=2} \atop {x=-3}} \right.$
