Question

(x-4) . (9-x)=0

Answer 1

x-4=0 hoặc 9-x=0

x=4 hoặc x=9

Vậy \(x\in\left\{4;9\right\}\)

Answer 2

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=9\end{matrix}\right.\)

Answer 3

\(\left(x-4\right).\left(9-x\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-4=0\\9-x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=9\end{matrix}\right.\)

vậy \(x=4\) hoặc \(9\)