(4-3x)(10x-5)=0
(=)\(\left[ \begin{array}{l}4-3x=0\\10x-5=0\end{array} \right.\) (=)\(\left[ \begin{array}{l}3x=4\\10x=5\end{array} \right.\) (=)\(\left[ \begin{array}{l}x=\frac{4}{3}\\x=\frac{1}{2}\end{array} \right.\)
(9-7x)(11-3x)=0
(=)\(\left[ \begin{array}{l}9-7x=0\\(11-3x=0\end{array} \right.\) (=)\(\left[ \begin{array}{l}7x=9\\3x=11\end{array} \right.\) (=)\(\left[ \begin{array}{l}x=\frac{9}{7}\\x=\frac{11}{3}\end{array} \right.\)
