Fighting!!!
Giải thích các bước giải:
`x^3 - 3x^2 + 3x -1 =0`
`<=>(x-1)^3=0`
`<=>x-1=0`
`<=>x=1`
Vậy `S={1}`
`(x^2 -9)+(x-3)(5-3x)=0`
`<=>(x-3)(x+3)+(x-3)(5-3x)=0`
`<=>(x-3)(x+3+5-3x)=0`
`<=>(x-3)(8-2x)=0`
$\Leftrightarrow\left[\begin{array}{I}x-3=0\\8-2x=0 \end{array}\right.\Leftrightarrow \left[\begin{array}{I} x=3\\ x=4\end{array}\right.$
Vậy `S={3;4}`
`(x^2-2x+1)=4`
`<=>x^2-2x+1-4=0`
`<=>x^2-2x-3=0`
`<=>x^2+x-3x-3=0`
`<=>x(x+1)-3(x+1)=0`
`<=>(x+1)(x-3)=0`
$\Leftrightarrow\left[\begin{array}{I}x+1=0\\x-3=0 \end{array}\right.\Leftrightarrow\left[\begin{array}{I} x=-1\\ x=3\end{array}\right.$
Vậy `S={-1;3}`
`4x^2 + 4x +1=x^2`
`<=>4x^2+4x+1-x^2=0`
`<=>3x^2+4x+1=0`
`<=>3x^2+3x+x+1=0`
`<=>3x(x+1)+(x+1)=0`
`<=>(x+1)(3x+1)=0`
$\Leftrightarrow\left[\begin{array}{I}x+1=0 \\3x+1=0\end{array}\right.\Leftrightarrow\left[\begin{array}{I} x=-1\\ x=-\dfrac13\end{array}\right.$
Vậy `S={-1;-1/3}`
`2x^2-6x=0`
`<=>2x(x-3)=0`
$\Leftrightarrow\left[\begin{array}{I}2x=0\\ x-3=0\end{array}\right.\Leftrightarrow\left[\begin{array}{I}x=0\\ x=3\end{array}\right.$
Vậy `S={0,3}`
`x(2x-7)-4x+14=0`
`<=>2x^2-7x-4x+14=0`
`<=>2x^2-4x-7x+14=0`
`<=>2x(x-2)-7(x-2)=0`
`<=>(x-2)(2x-7)=0`
$\Leftrightarrow\left[\begin{array}{I}x=2\\ x=\dfrac72\end{array}\right.$
Vậy `S={0;7/2}`
`x^2-5x+6=0`
`<=>x^2-2x-3x+6=0`
`<=>x(x-2)-3(x-2)=0`
`<=>(x-2)(x-3)=0`
$\Leftrightarrow \left[\begin{array}{I} x= 2\\ x=3\end{array}\right.$
Vậy `S={2;3}`
