Đáp án + giải thích các bước giải:
1/ `(x-2)(4x+5)=0`
`->`\(\left[ \begin{array}{l}x-2=0\\4x+5=0\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x=2\\4x=-5\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x=2\\x=\dfrac{-5}{4}\end{array} \right.\)
2/ `(5x+1)(x+3)(2x-5)=0`
`->`\(\left[ \begin{array}{l}5x+1=0\\x+3=0\\2x-5=0\end{array} \right.\)
`->`\(\left[ \begin{array}{l}5x=-1\\x=-3\\2x=5\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x=\dfrac{-1}{5}\\x=-3\\x=\dfrac{5}{2}\end{array} \right.\)
