Question

tính nhanh:
a. 53/101 x 13/97 x 53/101 x 84/97
b. 5/23 x 35/26 - 5/23 x 9/26
c. ( 1/2019 - 1/2020 + 1/2021) x ( 1/2 - 1/3 - 1/6)
d. (1+ 1/2) x (1+ 1/3) x (1+ 1/4) x (1+ 1/5) x (1+ 1/6) x (1+1/7)

Answer 1

`a) 53/101 xx 13/97 + 53/101 xx 84/97`

`= 53/101 xx ( 13/97 + 84/97)`

`= 53/101 xx 97/97`

`= 53/101 xx 1`

`= 53/101`

`b) 5/23 xx 35/26 - 5/23 xx 9/26`

`= 5/23 xx ( 35/26 - 9/26)`

`= 5/23 xx 26/26`

`= 5/23 xx 1`

`= 5/23`

`c)( 1/2019 - 1/2020 - 1/2021 ) xx ( 1/2 - 1/3 - 1/6)`

`= ( 1/2019 - 1/2020 - 1/2021 ) xx ( 3/6 - 2/6 - 1/6)`

`= ( 1/2019 - 1/2020 - 1/2021 )  xx 0`

`= 0`

`d)(1-1/2)xx(1-1/3)xx(1-1/4)xx(1-1/5)xx(1-1/6)`

`=1/2xx2/3xx3/4xx4/5xx5/4`

`=(1xx2xx3xx4xx5)/(2xx3xx4xx5xx4)`

`=(1xx\cancel2xx\cancel3xx\cancel4xx\cancel5)/(\cancel2xx\cancel3xx\cancel4xx\cancel5xx4)`

`=1/4`

Answer 2

cho mik hỏi hồi bạn học mầm non có học cùng bạn nào tên diệu linh ko ?