Câu trả lời:
ta có : \(x^2-x-6=0\)
\(\Leftrightarrow x^2-3x+2x-6=0\)
\(\Leftrightarrow x\left(x-3\right)+2\left(x-3\right)=0\)
\(\Leftrightarrow\left(x+2\right)\left(x-3\right)=0\)
\(\Rightarrow|^{x+2=0\Rightarrow x=-2}_{x-3=0\Rightarrow x=3}\)
vậy s=\(\left\{-2;3\right\}\)