Question

x^2-x=-2x+2

Answer 1

`x^2-x=-2x+2`

`<=>x^2+x-2=0`

Vì `a+b+c=0 => x_1=1; x_2=-2`

Vậy `S={1;-2}`.

Answer 2

\(x^2-x=-2x+2\Leftrightarrow x^2+x-2=0\Leftrightarrow x=1;x=-2\)

Answer 3

\(x^2-x=-2x+2\\ \Rightarrow x^2-x+2x-2=0\\ \Rightarrow x^2+x-2=0\\ \Rightarrow x^2+2x-x-2=0\\ \Rightarrow x\left(x+2\right)-\left(x+2\right)=0\\ \Rightarrow\left(x+2\right)\left(x-1\right)=0\\ \Rightarrow\left[{}\begin{matrix}x+2=0\\x-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-2\\x=1\end{matrix}\right.\)