`A = (2017 xx 2018 + 1)/(2017 xx 2018)`
`= (2017 xx 2018)/(2017 xx 2018) + 1/(2017 xx 2018)`
`= 1 + 1/(2017 xx 2018)`
`B = (2018 xx 2019 + 1)/(2018 xx 2019)`
`= (2018 xx 2019)/(2018 xx 2019) + 1/(2018 xx 2019)`
`= 1 + 1/(2018 xx 2019)`
Ta có:
`2017 < 2019`
`=> 2017 xx 2018 < 2018 xx 2019`
`=> 1/(2017 xx 2018) > 1/(2018 xx 2019)`
`=> 1 + 1/(2017 xx 2018) > 1 + 1/(2018 xx 2019)`
`=> A > B`
Vậy `A > B`