Đáp án:
`(2x-1)(x+1)-x(2x+3)=0`
`=> 2x^2+2x-x-1-2x^2-3x=0`
`=> -2x-1=0`
`=> -2x=1`
`=> x=-1/2`
`x(x-1)=2`
`=> x^2-x=2`
`=> x^2-x-2=0`
`=> x^2-2x+x-2=0`
`=> x(x-2)+(x-2)=0`
`=> (x-2)(x+1)=0`
`=>` \(\left[ \begin{array}{l}x-2=0\\x+1=0\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=2\\x=-1\end{array} \right.\)
