`1)x(x-1)-2(1-x)=0`
`=>x(x-1)+2(x-1)=0`
`=>(x-1)(x+2)=0`
\(\left[{}\begin{matrix}x-1=0\Rightarrow x=1\\x+2=0\Rightarrow x=-2\end{matrix}\right.\)
`2)x^3 - 3x^2 + 3x - 1=0`
`=> (x-1)^3 =0`
`=>x-1=0`
`=>x=1`
`3)x^2 -9=2(x+3)`
`=>(x+3)(x-3)-2(x+3)=0`
`=>(x+3)[(x-3)-2]=0`
`=>(x+3)(x-5)=0`
\(\left[{}\begin{matrix}x+3=0\Rightarrow x=-3\\x-5=0\Rightarrow x=5\end{matrix}\right.\)
`4)x^2 + 4x - 5x - 20 =0`
`=>x(x+4)-5(x+4)=0`
`=>(x+4)(x-5)=0`
\(\left[{}\begin{matrix}x+4=0\Rightarrow x=-4\\x-5=0\Rightarrow x=5\end{matrix}\right.\)
`5)4x(x+1)=8(x+1)`
`=>4x(x+1)-8(x+1)=0`
`=>(x+1)(4x-8)=0`
\(\left[{}\begin{matrix}x+1=0\Rightarrow x=-1\\4x-8=0\Rightarrow x=2\end{matrix}\right.\)
`6)x^2 + 20x - x - 20=0`
`=>x(x+20)-(x+20)=0`
`=>(x+20)(x-1)=0`
\(\left[{}\begin{matrix}x+20=0\Rightarrow x=-20\\x-1=0\Rightarrow x=1\end{matrix}\right.\)
`7)2x(x-1)-(1-x)^2=0`
`=>2x(x-1)+(x-1)^2=0`
`=>(x-1)[2x+(x-1)]=0`
`=>(x-1)(3x-1)=0`
\(\left[{}\begin{matrix}x-1=0\Rightarrow x=1\\3x-1=0\Rightarrow x=\dfrac{1}{3}\end{matrix}\right.\)
`8)x^3 - 6x^2 + 12x - 8 =0`
`=>(x-2)^3 = 0`
`=>x-2=0`
`=>x=2`
`9)x^3 + 27 + (x+3) (x-9)=0`
`=>(x+3)(x^2 -3x+9)+(x+3)(x-9)=0`
`=>(x+3)[(x^2-3x+9)+(x-9)]=0`
`=>(x+3)(x^2 -2x)=0`
`=>x(x+3)(x-2)=0`
\(\left[{}\begin{matrix}x=0\\x+3=0\Rightarrow x=-3\\x-2=0\Rightarrow x=2\end{matrix}\right.\)
a: =>(x-1)(x+2)=0
=>x=1 hoặc x=-2
b: =>(x-1)^3=0
=>x=1
c: =>(x-3)(x+3)-2(x+3)=0
=>(x+3)(x-5)=0
=>x=5 hoặc x=-3
d: =>x(x+4)-5(x+4)=0
=>(x+4)(x-5)=0
=>x=5 hoặc x=-4
e: =>(x+1)(4x-8)=0
=>x=2 hoặc x=-1
h: =>(x-2)^3=0
=>x=2
f: =>(x+20)(x-1)=0
=>x=1 hoặc x=-20
i: =>(x+3)(x^2-3x+9)+(x+3)(x-9)=0
=>(x+3)(x^2-2x)=0
=>x=0; x=2;x=-3