a][4-x][x-3]=0 b]2x-8][1-x]=0 c][15-3x][x-6]=0

${a)(4-x)(x-3)=0}$
⇒\(\left[ \begin{array}{l}4-x=0\\x-3=0\end{array} \right.\) 
⇒\(\left[ \begin{array}{l}x=4\\x=3\end{array} \right.\)

$\text{Vậy \(\left[ \begin{array}{l}x=4\\x=3\end{array} \right.\)}$

${b)(2x-8)(1-x)=0}$

⇒\(\left[ \begin{array}{l}2x-8=0\\1-x=0\end{array} \right.\) 
⇒\(\left[ \begin{array}{l}2x=8\\x=1-0\end{array} \right.\)

⇒ \(\left[ \begin{array}{l}x=4\\x=1\end{array} \right.\)

$\text{Vậy \(\left[ \begin{array}{l}x=4\\x=1\end{array} \right.\)}$

${b)(15-3x)(x-6)=0}$

⇒\(\left[ \begin{array}{l}15-3x=0\\x-6=0\end{array} \right.\) 
⇒\(\left[ \begin{array}{l}3x=15\\x=0+6\end{array} \right.\)

⇒ \(\left[ \begin{array}{l}x=5\\x=6\end{array} \right.\)

$\text{Vậy \(\left[ \begin{array}{l}x=5\\x=6\end{array} \right.\)}$

$\text{STUDY WELL !}$