mn ơi giúp e (x-7)(2x+8)=0 mn giúp e vs ạ 27/10/2021 Bởi Isabelle mn ơi giúp e (x-7)(2x+8)=0 mn giúp e vs ạ
`(x-7)(2x+8)=0` `<=> 2(x-7)(x+4)=0` `<=>`\(\left[ \begin{array}{l}x-7=0\\x+4=0\end{array} \right.\) `<=>`\(\left[ \begin{array}{l}x=7\\x=-4\end{array} \right.\) Vậy `S={7;-4}` Bình luận
$(x-7)(2x+8)=0$ \(\leftrightarrow\left[ \begin{array}{l}x-7=0\\2x+8=0\end{array} \right.\) \(\leftrightarrow\left[ \begin{array}{l}x=7\\2x=-8\end{array} \right.\) \(\leftrightarrow\left[ \begin{array}{l}x=7\\x=-4\end{array} \right.\) Bình luận
`(x-7)(2x+8)=0`
`<=> 2(x-7)(x+4)=0`
`<=>`\(\left[ \begin{array}{l}x-7=0\\x+4=0\end{array} \right.\)
`<=>`\(\left[ \begin{array}{l}x=7\\x=-4\end{array} \right.\)
Vậy `S={7;-4}`
$(x-7)(2x+8)=0$
\(\leftrightarrow\left[ \begin{array}{l}x-7=0\\2x+8=0\end{array} \right.\) \(\leftrightarrow\left[ \begin{array}{l}x=7\\2x=-8\end{array} \right.\) \(\leftrightarrow\left[ \begin{array}{l}x=7\\x=-4\end{array} \right.\)