Đáp án:
Giải thích các bước giải:
Ta có :
`A = |x - 2019| + |x - 2020| + |y - 2021| + |x - 2022| + 2016`
`=> A = |x-2019|+|2022-x|+|x-2020|+|y-2021|+2016`
`=> A ≥ |x-2019+2022-x|+0+0+2016`
`=> A ≥ 2019`
Vậy `A_min=2019` $⇔ \left\{\begin{matrix} (x-2019)(2022-x)≥0& \\ y-2021=0& \\ x-2020=0& \end{matrix}\right.$
$⇔ \left\{\begin{matrix} (x-2019)(2022-x)≥0& \\ y=2021& \\ x=2020& \end{matrix}\right.$