Question

(-x + 1) . (x - 2) = 0

-x : (x + 7)= 0

Answer 1

`#3107.101107`

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

Vậy, `x \in {1; 2}`

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\(-x\div\left(x+7\right)=0\\ \Rightarrow\left[{}\begin{matrix}-x=0\\x+7\ne0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=0\\x\ne-7\end{matrix}\right.\)

Vậy, `x = 0 (tm).`