Đáp án `+` Giải thích các bước giải:
` d) x(x-4) +5(x-4) = 0 `
` -> (x-4)(x+5) = 0 `
` -> ` \(\left[ \begin{array}{l}x-4=0\\x-5=0\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=4\\x=-5\end{array} \right.\)
Vậy .....
` e) 3x(x+1) - 6(x+1)=0 `
`-> (x+1)(3x-6)=0 `
`->` \(\left[ \begin{array}{l}x+1=0\\3x-6=0\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=-1\\3x=6\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=-1\\x=2\end{array} \right.\)
Vậy ..........
` f) 5x(x-3) + 10(3-x) =0 `
`-> 5x(x-3) - 10(x-3)=0 `
`-> (x-3)(5x-10)=0 `
`->` \(\left[ \begin{array}{l}x-3=0\\5x-10=0\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=3\\5x=10\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=3\\x=2\end{array} \right.\)
Vậy..
