1) -7/12 + 11/20 – 8/15 2) 9/11 + ( -2/5 + 1/6 ) : 11/30 3) (5/7 . 0,6 – 5 : 3 1/2 ) . ( 40% – 1,4 ) . (-2)³

0 bình luận về “1) -7/12 + 11/20 – 8/15 2) 9/11 + ( -2/5 + 1/6 ) : 11/30 3) (5/7 . 0,6 – 5 : 3 1/2 ) . ( 40% – 1,4 ) . (-2)³”

1. Đáp án:

   `1) \ – 17/30`

   `2) \ 2/11`

   `3) \ -8`

   Giải thích các bước giải:

   `1)`

   `-7/12+11/20-8/15`

   `=-35/60+33/60-32/60`

   `=(-35+33-32)/60= -34/60=-17/30`

   `2)`

   `9/11+(-2/5+1/6):11/30`

   `=9/11+(-12/30+5/30).30/11`

   `=9/11+(-7)/30 . 30/11`

   `=9/11-7/11=2/11`

   `3)`

   `(5/7 . 0,6 – 5 : 3 1/2) . ( 40% – 1,4 ) . (-2)^3`

   `= (5/7 . 3/5 – 5 : 7/2) . ( 2/5 – 7/5 ) . (-8)`

   `= (3/7-10/7) . (-5)/5 . (-8)`

   `= (-7)/7 . (-1) . (-8) = (-1) . (-1) . (-8) `

   `=-8`

    

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2. 1)

   `-7/12 + 11/20 – 8/15`

   `= -35/60 + 33/60 – 32/60`

   `= -2/60 -32/60`

   `= -34/60 = -17/30`

   2)

   `9/11 + (-2/5 + 1/6): 11/30`

   `= 9/11 + (-7/30) : 11/30`

   `= 9/11 + (-7/30). 30 /11`

   `= 9/11+ (-7/11)`

   `=2/11`

   3)

   `(5/7 . 0,6 – 5: 3 1/2). (40% – 1,4) . (-2)^3`

   `= (5/7. 3/5 – 5: 7/2) . (2/5 -7/5) . (-8)`

   `=( 3/7 – 5. 2/7) . (-1) . (-8)`

   `= ( 3/7- 10/7) . 8`

   `= -1. 8`

   `= -8`

    

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