Đáp án:

 `a)9/101`

`b)-8/3`

`c)0`

`d)-\frac{323}{117}`

`e)-6`

Giải thích các bước giải:

 `a)`

`(9)/(100). (23)/(101)+9/100. 81/101-9/100. 4/101`

`=9/100. (23/101+ 81/101- 4/101)`

`=9/100. \frac{100}{101}`

`=\frac{9.100}{100.101}`

`=9/101`

`b)`

`(1/4-2/5):3/8+(3/4-8/5): 3/8`

`=(1/4-2/5). 8/3+(3/4-8/5). 8/3`

`=8/3. (1/4-2/5+3/4-8/5)`

`=8/3. [(1/4+3/4)-(2/5+8/5)]`

`=8/3. (4/4-10/5)`

`=8/3. (-1)`

`=-8/3`

`c)`

`(4/15+3/5): 5/6+(11/15-8/5): 5/6`

`=(4/15+3/5). 6/5+(11/15-8/5). 6/5`

`=6/5. (4/15+3/5+11/15-8/5)`

`=6/5.[(4/15+11/15)+(3/5-8/5)]`

`=6/5. (15/15-5/5)`

`=6/5. (1-1)`

`=6/5. 0`

`=0`

`d)`

`11/15. (\frac{-19}{13})+11/15. (-7/3)+4/5`

`=11/15.[(-19/13)+(-7/3)]+4/5`

`=11/15.(-57/39-91/39)+4/5`

`=11/15. (-(148)/(39))+4/5`

`=\frac{-1628}{585}+4/5`

`=\frac{-1628}{585}+\frac{468}{585}`

`=\frac{-1160}{585}`

`=-\frac{323}{117}`

`e)`

`5/2:(-5/3)-7 1/2. 3/5`

`=5/2. (-3/5)-(7+1/2). 3/5`

`=3/5.[(-1). 5/2-(7+1/2)]`

`=3/5.[(-5/2)-7-1/2]`

`=3/5. (-6/2-7)`

`=3/5. (-3-7)`

`=3/5. (-10)`

`=(-30)/(5)`

`=-6`