Đáp án:
Giải thích các bước giải:
Bài 2 :
`a)`
`1 1/5+5/9+4/5+4/9`
`=6/5+5/9+4/5+4/9`
`=(6/5+4/5)+(5/9+4/9)`
`=10/5+9/9`
`=2+1`
`=3`
`b)`
`2/7-(3 4/9+2/7)`
`=2/7-31/9-2/7`
`=(2/7-2/7)-31/9`
`=0-31/9`
`=-31/9`
`c)`
`(2-7/10):(5/7+3/14)+6^0`
`=(20/10-7/10):(10/14+3/14)+1`
`=13/10:13/14+1`
`=13/10 . 14/13+1`
`=7/5+1`
`=7/5+5/5`
`=12/5`
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