`( x - 2019 )( x - 2020 ) = 0`
`@ TH1`
`x-2019=0`
`x=0+2019`
`x=2019`
` @ TH2`
`x-2020=0`
`x=0+2020`
`x=2020`
\(\text{( x – 2019 ) ( x – 2020 ) = 0}\)
\(\text{+) x – 2019 = 0 }\)\(\Rightarrow\text{x = 2019}\)
\(\text{+) x – 2020 = 0}\) \(\Rightarrow\text{x = 2020}\)
Có: (x - 2019)(x - 2020) = 0
=> \(\left[{}\begin{matrix}x-2019=0\\x-2020=0\end{matrix}\right.\) => \(\left[{}\begin{matrix}x=2019\\x=2020\end{matrix}\right.\)
Vậy x ∈ {2019; 2020}
`(x-2019)(x-2020) = 0`
\(\Rightarrow\left\{{}\begin{matrix}x-2019=0\\x-2020=0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=2019\\x=2020\end{matrix}\right.\)