Tính a) -10/13 + 5/17 – 3/13 + 12/17 – 11/20 b) 3/4 + -5/6 – 11/-12 c) ( 13 và 4/9 + 2 và 1/9 ) – 3 và 4/9 d) 1,25 : 15/20 + ( 25% – 5/6 ) : 4 và 2/3

0 bình luận về “Tính a) -10/13 + 5/17 – 3/13 + 12/17 – 11/20 b) 3/4 + -5/6 – 11/-12 c) ( 13 và 4/9 + 2 và 1/9 ) – 3 và 4/9 d) 1,25 : 15/20 + ( 25% – 5/6 ) : 4 và 2/3”

1. a) `-10/13` + `5/17` – `3/13` + `12/17` – `11/20`

   = ( `-10/13` – `3/13`) + ( `5/17` + `12/17`) – `11/20`

   = `-13/13` + `17/17` – `11/20`

   = (-1) + 1 – `11/20`

   = 0 – `11/20`

   = `-11/20`

   b) `3/4` + `-5/6` – `11/-12`

   = `9/12` + `-10/12` – `-11/12`

   = `-1/12` – `-11/12`

   = `10/12`

   = `5/6`

   c) ( 13`4/9` + 2`1/9` ) – 3`4/9`

   =  `121/9` + `19/9` –  `31/9`

   = `140/9` – `31/9`

   =`109/9`

   d) `1,25` : `15/20` + ( 25% – `5/6` ) : 4`2/3`

   = `5/4` : `3/4` + ( `1/4` – `5/6`) : `14/3`

   = `5/3` + `-7/12` : `14/3`

   = `5/3` + `-7/12` . `3/14`

   = `5/3` + `1/8`

   = `40/24` + `3/14`

   = `43/24`

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2. `(-10)/13 + 5/17 – 3/13 + 12/17 – 11/20`

   `= ((-10)/13 – 3/13) + (5/17 + 12/17) – 11/20`

   `= -1 + 1 – 11/20`

   `= 0 – 11/20`

   `= (-9)/20`

   `3/4 + (-5)/6 – 11/-12`

   `= 3/4 – 5/6 + 11/12`

   `= 9/12 – 10/12 + 11/12`

   `= (9 – 10 + 11)/12`

   `= 5/6`

   `(13 4/9 + 2 1/9) – 3 4/9`

   `= 13 4/9 + 2 1/9 – 3 4/9`

   `= (13 + 2 – 3) + (4/9 + 1/9 – 4/9)`

   `= 12 + 1/9`

   `= 12 1/9`

   `1,25 : 15/20 + (25% – 5/6) : 4 2/3`

   `= 5/4 . 20/15 + (1/4 – 5/6) : 14/3`

   `= 5/3 + (-7)/12 . 3/14`

   `= 5/3 – 7/12 . 3/14`

   `= 5/3 – 1/8`

   `= 37/24`

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