1/ x.(x + 7) = 0
(=)\(\left[ \begin{array}{l}x=0\\x+7=0\end{array} \right.\) (=)\(\left[ \begin{array}{l}x=0\\x=-7\end{array} \right.\)
2/ (x + 12).(x-3) = 0
(=)\(\left[ \begin{array}{l}x+12=0\\x-3=0\end{array} \right.\) (=)\(\left[ \begin{array}{l}x=-12\\x=3\end{array} \right.\)
3/ (-x + 5).(3 – x ) = 0
(=)\(\left[ \begin{array}{l}-x+5=0\\3-x=0\end{array} \right.\) (=)\(\left[ \begin{array}{l}-x=-5\\-x=-3\end{array} \right.\) (=)\(\left[ \begin{array}{l}x=5\\x=3\end{array} \right.\)
4/ x.(2 + x).( 7 – x) = 0
1)x=0
2)2+x=0(=)x=-2
3)-x-3=0=)-x=3=)x=-3
5/ (x - 1).(x +2).(-x -3) = 0
1)x-1=0=)x=1
2)x+2=0=)x=-2
3)-x-3=0=)-x=3=)x=-3
