Mong được giúp ạ :(((((

Đáp án + Giải thích các bước giải:

Bài `1`:

a) `31.72-31.70-31.2`

`=31.(72-70-2)`

`=31.0`

`=0`

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b) `-12.47-12.52-12`

`=-12.(47+52+1)`

`=-12.100`

`=-1200`

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c) `-29.13-29.27+29.14`

`=29.(-13-27+14)`

`=29.(-26)`

`=-754`

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d) `-48-48.78-48.21`

`=-48.(1+78+21)`

`=-48.100`

`=-4800`

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e) `-17.37-23.37+46.37`

`=37.(-17-23+46)`

`=37.6`

`=222`

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f) `34.157+34.12-69.34`

`=34.(157+12-69)`

`=34.100`

`=3400`

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i) `61.141+59.141-141.20`

`=141.(61+59-20)`

`=141.100`

`=14100`

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j) `-41.18-81.41-41`

`=-41.(18+81+1)`

`=-41.100`

`=-4100`

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k) `27.121-87.27+27.16`

`=27.(121-87+16)`

`=27.50`

`=1350`

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l) `129.172-83.129+129.11`

`=129.(172-83+11)`

`=129.100`

`=12900`