11. Tính giá trị biểu thức a) 3/5 : ( 1/2 . 3/5 ) b) 4/5 + 3/5 : 3 – 7/8 c) ( 3/4 : 2/3 ) : 3/5 d) ( 5/12 . 21/15 ) : 1/4

0 bình luận về “11. Tính giá trị biểu thức a) 3/5 : ( 1/2 . 3/5 ) b) 4/5 + 3/5 : 3 – 7/8 c) ( 3/4 : 2/3 ) : 3/5 d) ( 5/12 . 21/15 ) : 1/4”

1. $a$) `3/5 : (1/2 . 3/5)`

   `= 3/5 : 3/{10}`

   `= 3/5 . {10}/3`

   `= 2`. 

   $b$) `4/5 + 3/5 : 3 – 7/8`

   `= 4/5 + 3/5 . 1/3 – 7/8`

   `= 4/5 + 1/5 – 7/8`

   `= 1 – 7/8`

   `= 1/8`

   $c$) `(3/4 : 2/3) : 3/5`

   `= (3/4 . 3/2) . 5/3`

   `= 9/8 . 5/3`

   `= 15/8`.

   $d$) `(5/12 . 21/15) : 1/4`

   `= 7/12 . 4`

   `= 7/3`.

    

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2. Đáp án:

   `a) 3/5 : ( 1/2 . 3/5 )`

   `= 3/5 : 3/10`

   `= 3/5 . 10/3`

   `= 2`

   `b) 4/5 + 3/5 : 3 – 7/8`

   `= 4/5 + 3/5 . 1/3 – 7/8`

   `= 4/5 + 1/5 – 7/8`

   `= 1 – 7/8`

   `= 1/8`

   `c) ( 3/4 : 2/3 ) : 3/5`

   `= (3/4 . 3/2) : 3/5`

   `= 9/8 : 3/5`

   `= 9/8 . 5/3`

   `= 15/8`

   `d) ( 5/12 . 21/15 ) : 1/4`

   `= 7/12 : 1/4`

   `= 7/12 . 4`

   `= 7/3`

    

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