a) 6/7+-8/9 b)-5/21 c)13/12+ -17/36 – -13/18

0 bình luận về “a) 6/7+-8/9 b)-5/21 c)13/12+ -17/36 – -13/18”

1. Đáp án:

   a) `6/7`+`-8/9`

   =`54/63`+`-56/63`

   =`-2/63`

   b) `-5/21` – `19/28`

   =`-11/12`

   c)`13/12`+ `-17/36` – -`13/18`

   =`156/144`-`153/144`–`104/144`

   =`3/144`+`104/144`

   =`107/144`

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2. a) `6/7` + `-8/9` = `54/63` + ` -56/63`= `-2/63`

   b) `-5/21` = `-5/21` ( có ghi sai đề không bạn )

   c )  `13/12` + `-17/16` – `-13/18`

   = `156/144` – `153/144` + `104/144`

   = `107/144`

    

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