Bài 1:b Vận dụng tính nhanh a) 20152015.2014-20142014.2015 b) 123.456456-456.123123 c) (98.7676-9898.76):( 2001.2002.2003…….2010)

`Đáp` `án` :

`a`) ${0}$ 

`b`) ${0}$ 

`c`) ${0}$ 

`Giải` `thích` `các` `bước` `giải` :

a) ${20152015}$ . ${2014}$ – ${20142014}$ . ${2015}$ 

= ${10001}$ . ${2015}$ . ${2014}$ – ${10001}$ . ${2014}$ . ${2015}$ 

= ${0}$ 

b) ${123}$ . ${456456}$ – ${456}$ . ${123123}$

= ${123}$ . ${1001}$ . ${456}$ – ${456}$ . ${1001}$ . ${123}$

= ${0}$ 

c) ( ${98}$ . ${7676}$ – ${9898}$ . ${76}$ ) : ( ${2001}$ . ${2002}$ . ${2003}$…….${2010}$ )

= (  ${98}$ . ${101}$ . ${76}$ – ${101}$ . ${98}$ . ${76}$ ) : ( ${2001}$ . ${2002}$ . ${2003}$…….${2010}$ )

= ${0}$  :  ( ${2001}$ . ${2002}$ . ${2003}$…….${2010}$ ) 

= ${0}$ 

@`Dịu` `gửi` `bạn`

`Chúc` `bạn` `học` `tốt` !