6.
`(1988 × 1996 + 1997 × 11 + 1985)/(1997 × 1996 - 1995 × 1996)`
`⇔ (3968048+21967+1985)/(1997 × 1996 - 1995 × 1996)`
`⇔ (3990015+1985)/(1997 × 1996 - 1995 × 1996)`
`⇔ (3992000)/(3986012−1995×1996)`
`⇔ (3992000)/(3986012−3982020)`
`⇔ (3992000)/(3992)`
`⇔ 1000/1`
`⇔ 1000`
`→` Chọn `B`
Cho mình xin hay nhất nha bạn!!!!!!
@Drew Mclntyre