Đáp án:
c)
`(15 - 3x)(x - 6) = 0`
`=>` \(\left[ \begin{array}{l}15-3x=0\\x-6=0\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}3x=15\\x=0+6\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=5\\x=6\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=5\\x=6\end{array} \right.\)
Vậy `x = 5` hoặc `x = 6`.
Chúc học tốt!!!