Đáp án:
`1.(x+1).(x-2)=0`
⇒\(\left[ \begin{array}{l}x+1=0\\x-2=0\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=2\\x=-1\end{array} \right.\)
`2.(x-2).(x+2/3)>0`
`⇒GTLN của (x-2).(x+2/3)=0`
Dấu "=" xảy ra khi
⇒\(\left[ \begin{array}{l}x-2=0\\x+2/3=0\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=2\\x=-2/3\end{array} \right.\)