1: =>(x-3)(x-2)=0
=>x=3 hoặc x=2
b: =>(x-3)(x-4)=0
=>x=3 hoặc x=4
3: =>(x+2)(x+3)=0
=>x=-2 hoặc x=-3
4: =>(x+3)(x+4)=0
=>x=-3 hoặc x=-4
\(1,\Leftrightarrow x^2-2x-3x+6=0\\ \Leftrightarrow\left(x-2\right)\left(x-3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2\\x=3\end{matrix}\right.\\ 2,\Leftrightarrow x^2-3x-4x+12=0\\ \Leftrightarrow\left(x-3\right)\left(x-4\right)=0\Leftrightarrow\left[{}\begin{matrix}x=3\\x=4\end{matrix}\right.\\ 3,\Leftrightarrow x^2+2x+3x+6=0\\ \Leftrightarrow\left(x+2\right)\left(x+3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=-3\end{matrix}\right.\\ 4,\Leftrightarrow x^2+3x+4x+12=0\\ \Leftrightarrow\left(x+3\right)\left(x+4\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-4\\x=-3\end{matrix}\right.\\ 5,\Leftrightarrow x^2-4x+3x-12=0\\ \Leftrightarrow\left(x-4\right)\left(x+3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-3\end{matrix}\right.\)
\(6,\Leftrightarrow2x^2+x-4x-2=0\\ \Leftrightarrow\left(2x+1\right)\left(x-2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=2\end{matrix}\right.\\ 7,\Leftrightarrow3x^2+3x-2x-2=0\\ \Leftrightarrow\left(x+1\right)\left(3x-2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=\dfrac{2}{3}\end{matrix}\right.\\ 8,\Leftrightarrow4x^2-8x+x-2=0\\ \Leftrightarrow\left(x-2\right)\left(4x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-\dfrac{1}{4}\end{matrix}\right.\\ 9,\Leftrightarrow4x^2-3x+8x-6=0\\ \Leftrightarrow\left(4x-3\right)\left(x+2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{4}\\x=-2\end{matrix}\right.\\ 10,\Leftrightarrow3x^2+9x+x+3=0\\ \Leftrightarrow\left(x+3\right)\left(3x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-\dfrac{1}{3}\end{matrix}\right.\)
