b, `-18/25` + `-2014/2015` + `7/8` + `9/8` + `-32/25` c, `-7/18` + `4/9` – `-5/12` d, `-9/13`+ `1/7` + `-1/2015` + `13/7` + `-17/13`

0 bình luận về “b, `-18/25` + `-2014/2015` + `7/8` + `9/8` + `-32/25` c, `-7/18` + `4/9` – `-5/12` d, `-9/13`+ `1/7` + `-1/2015` + `13/7` + `-17/13`”

1. $b)$

   `-18/25 – 2014/2015 + 7/8 + 9/8 – 32/25`

   `= (-18/25 – 32/25) + (7/8 + 9/8) – 2014/2015`

   `= -2 + 2 – 2014/2015`

   `= -2014/2015`

   $c)$

   `-17/18 + 4/9 – {-5}/12`

   `= -34/36 + 16/36 + 15/12`

   `=-6/12`

   `= -1/2` 

   $d)$

   `-9/13 + 1/7 – 1/2015 + 13/7 – 17/13`

   `= (-9/13 – 17/13) + (1/7 + 13/7) – 1/2015`

   `= -2 + 2 – 1/2015`

   `= -1/2015`

    

   Trả lời

2. `b, (-18)/25 + (-2014)/2015 + 7/8 + 9/8 + (-32)/25`

   `= ((-18)/25 + (-32)/25) + (-2014)/2015 + (7/8 + 9/8)`

   `= -2 + (-2014)/2015 + 2`

   `= (-2014)/2015`

   `c, -7/18 + 4/9 – (-5)/12`

   `= 1/18 + 5/12`

   `= 17/36`

   `d, (-9)/13 + 1/7 + (-1)/2015 + 13/7 + (-17)/13`

   `= ((-9)/13 + (-17)/13) + (1/7 + 13/7) + (-1)/2015`

   `= -2 + 2 + (-1)/2015`

   `= (-1)/2015`

   Trả lời