Đề bài : tính nhanh Giúp mình với

1) 

`7/13 – 4/5 + 9/5 -33/13`

`= (7/13 -33/13) + ( -4/5 + 9/5 )`

`= -2+ 1`

`=-1`

2)

`4 4/9 -( 2 2/7 + 3 4/9)`

`= 4 4/9 – 2 2/7 – 3 4/9`

`= 1 – 2 2/7`

`= 1 -16/7`

`=-9/7`

3) 

`360 . (13/180 – 7/120 + 1/450)`

`= (360.13)/180 – (360.7)/120 + 360/450`

`= 2. 13 – 3.7 +4/5`

`= 26 – 21 + 4/5`

`=5 + 4/5`

`=29/5`

4)

`-5/11 . 4/17 + 2/33 + (-4/17) . 12/11`

`= -5/11 . 4/17 + 2/33 + 4/17 . (-12/11)`

`= 4/17[(-5/11) + (-12/11)] + 2/33`

`=4/17 .(-17/11) + 2/33`

`= -4/11 + 2/33`

`= -10/33`

5)

`(-45/7 : 13/23 + (-45/7) . 3/13) : 45`

`= ( -45/7 . 23/13 + (-45/7) . 3/13) :45`

`= -45/7(23/13 + 3/13) : 45`

`= -45/7 . 2 . 1/45`

`=-2/7`

6)

`13/15 (15/13 -2) – 8/45 .( 45+ 3/2)`

`= 13/15 . 15/13 – 2 . 13/15 – 8/45 . 45 – 8/45 . 3/2`

`= 1- 26/15 -8 -4/15`

`= -7 – 2`

`=-9`