Tính a, `-9/34“*17/4` b, `-20/41“*-4/5` c, `-15*2/3` d, `-5/2:3/4` e, `4“1/5:(-2“4/5)` g, `1“4/5:(-3/4)`

0 bình luận về “Tính a, `-9/34“*17/4` b, `-20/41“*-4/5` c, `-15*2/3` d, `-5/2:3/4` e, `4“1/5:(-2“4/5)` g, `1“4/5:(-3/4)`”

1. `a) -9/34 . 17/4`

   `=\frac{-9 . 17}{34.4}`

   `=\frac{-9 . 1}{2.4}`

   `= -9/8`

   ——————————

   `b) -20/41 . (-4/5)`

   `= \frac{-20 . (-4)}{41.5}`

   `= \frac{-4. (-4)}{41.1}`

   `= 16/41`

   ———————————–

   `c) -15 . 2/3`

   `= \frac{-15 . 2}{3}` 

   `=\frac{-5 . 2}{1}`

   `= -10/1`

   `= -10`

   ————————————-

   `d) -5/2 : 3/4`

   `= -5/2 . 4/3`

   `= \frac{-5 . 4}{2 . 3}`

   `= \frac{-5 . 2}{1 . 3}`

   `= -10/3`

   ————————————-

   `e) 4 1/5 : ( -2 4/5)`

   `= 21/5 : ( -14/5)`

   `= 21/5 . (-5/14)`

   `=\frac{21 . (-5)}{5 . 14}`

   `= \frac{21 . (-1)}{1 . 14}`

   `= -21/14`

   `=-3/2`

   ——————————————-

   `g) 1 4/5 : (-3/4)`

   `= 9/5 . (-4/3)`

   `= \frac{9 . (-4)}{5 . 3}`

   `= \frac{3 . (-4)}{5 . 1}`

   `= -12/5`

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2. a,`\frac{-9}{34} .\frac{17}{4} `=`\frac{-9}{2.17}.\frac{17}{4}`=`\frac{-9}{2.4}`=`\frac{-9}{8}`

   b,`\frac{-20}{41}.\frac{-4}{5}=\frac{-4.5}{41}.\frac{-4}{5}=\frac{-4.-4}{41}=\frac{16}{41}`

   c,`-15.\frac{2}{3}=-5.3.\frac{2}{3}=-5.2=-10`

   d,`\frac{-5}{2}:\frac{3}{4}`=`\frac{-5}{2}.\frac{2.2}{3}`=`\frac{-5.2}{3}`=`\frac{-10}{3}`

   e,`4\frac{1}{5}:(-2\frac{4}{5})`=`\frac{21}{5}:(\frac{-14}{5})`=`\frac{7.3}{5}.\frac{5}{7.-2}`=`\frac{-3}{2}`

   g`1\frac{4}{5}:(\frac{-3}{4})`=`\frac{-3.-3}{5}.\frac{4}{-3}`=`\frac{-3.4}{5}`=`\frac{-12}{5}`

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