Question

Giải pt (-x+2)(-3x-15)=0

Answer 1

` (-x+2)(-3x-15)=0`

\(\Leftrightarrow\left[{}\begin{matrix}-x+2=0\\-3x-15=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}-x=-2\\-3x=15\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-5\end{matrix}\right.\)

Vậy `S={2;-5}`

Answer 2

`(-x+2)(-3x-15)=0`

`<=>` $\left[\begin{matrix} -x+2=0\\ -3x-15=0\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=2\\ x=-5\end{matrix}\right.$

Vậy `S={2;-5}`

Answer 3

\(\Leftrightarrow\left[{}\begin{matrix}-x+2=0\\-3x-15=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-5\end{matrix}\right.\)