`x(x-5)+2x-10=0`
`<=> x(x-5)+2(x-5)=0`
`<=>(x-5)(x+2)=0`
\(\Leftrightarrow\left[{}\begin{matrix}x-5=0\\x+2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5\\x=-2\end{matrix}\right.\)
\(x\left(x-5\right)+2x-10=0\)
\(\Leftrightarrow x^2-5x+2x-10=0\)
\(\Leftrightarrow x^2-3x-10=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}x_1=5\\x_2=-2\end{matrix}\right.\)
= \(x(x-5)+(2x-10)\)
\(=x(x-5)+2(x-5)\)
\(=(x-5)(x+2)\)
\(\Rightarrow\) \(x-5=0\) \(hoặc\) \(x+2=0\)
\(\Rightarrow\) \(x=5\) hoặc \(x=-2\)
