Đề cương cô giao trên azotannnnnn

Đáp án:

`a)` ` -1/20`

`b)` `-3,71`

`c)` `-4084431`

`d)` `-7/2`

Giải thích các bước giải:

 `a)` `-3/28-{-18}/{315}`

`=-135/1260+{72}/{1260}`

`=-63/1260`

`=-1/20`

`b)` `(-0,5)^2 .(-3,71).4`

`=(1/2)^2 .(-3,71).4`

`=1/4 . 4.(-3,71)`

`=4/4 .(-3,71)`

`=1 . (-3,71)`

`=-3,71`

`c)` `8{1}/4:(-9/5)-26{1}/4:(-9/5)-(-2021)^2`

`=(8{1}/4-26{1}/4):(-9/5)-2021^2`

`=(33/4-105/4):(-9/5)-2021^2`

`=(-72/4):(-9/5)-2021^2`

`=-18 . (-5/9) -2021^2`

`=-18 . (-5/9) -2021^2`

`=90/9-2021^2`

`=10-2021^2`

`=10-4084441`

`=-4084431`

`d)` `[(-1/3)^2 . 27/7 +\sqrt{16/49}-3]:4/7`

`=[1/9 . 27/7 +4/7-3]:4/7`

`=[1/1 . 3/7 +4/7-21/7]:4/7`

`=[3/7 -17/7]:4/7`

`=-14/7 . 7/4`

`=-7 . 1/2`

`=-7/2`