Đáp án:
Giải thích các bước giải:
a) B`=121.124`
`=>`B`=(123-2).124`
`=>`B`=123.124-2.124`
`=>`B`=123.(123+1)-2.124`
`=>`B`=123.123+123-2.124`
`=>`B`=123.123+123-2.(123+1)`
`=>`B`=123.123+123-2.123-2`
`=>`B`=123.123+123.(1-2)-2`
`=>`B`=123.123-123-2`
`=>`B`=123.123-125<123.123=`A
`=>`A`>`B
Vậy A`>`B.
b) C`=123.137137`
`=>`C`=123.137.1001`
`=>`D`=137.123123`
`=>`D`=137.123.101=`C.
`=>`C`=`D
Vậy C`=`D.
c) C`=137.454+206`
`=>`C`=(138-1).454+206`
`=>`C`=138.454-454+206`
`=>`C`=138.454-248`
`=>`C`=138.(453+1)-248`
`=>`C`=138.453+138-248`
`=>`C`=138.453-110=`D
`=>`C`=`D.
Vậy C`=`D.
d) M`=2020.2022`
`=>`M`=(2021-1).2022`
`=>`M`=2021.2022-2022`
`=>`M`=2021.(2021+1)-2022`
`=>`M`=2021.2021+2021-2022`
`=>`M`=2021.2021-1<2021^2=`N
`=>`M`<`N.
Vậy M`<`N.