1) -2 + 9 + (-27) : 3 2) -2/5 – -5/2 + 3/5 3) 5/7 . 9/11 + 5/7 + 3/5 4) 1/10 – 3/5 – -1/2 5) -5/7 . 9/11 + -5/7 . 2/11 + 1 5/7

0 bình luận về “1) -2 + 9 + (-27) : 3 2) -2/5 – -5/2 + 3/5 3) 5/7 . 9/11 + 5/7 + 3/5 4) 1/10 – 3/5 – -1/2 5) -5/7 . 9/11 + -5/7 . 2/11 + 1 5/7”

1. `1)-2+9+(-27):3`

   `=-2+9+ -9`

   `=-2`

   `2)-2/5- -5/2+3/5`

   `=-2.1+0,6`

   `=-1,5`

   `3)5/7 . 9/11+5/7+3/5`

   `= 45/77+5/7+3/5`

   `=100/77+3/5`

   `=300/385+231/385`

   `=531/385`

   `4)1/10-3/5- -1/2`

   `=-5/10- -1/2`

   `=0`

   `5)-5/7 . 9/11 + -5/7 . 2/11+ 1 5/7`

   `= -5/7.(9/11+2/11)+12/7`

   `=-5/7 . 1+12/7`

   `=1`

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2. 1) (-2) + 9 + (-27) : 3

   =(-2) +{9 + (-9)}
   =(-2)+0
   =-2

   2) (-2/5) – (-5/2) + 3/5
   =(-2/5)-(-2/5)+3/5
   =0+3/5
   =3/5
   3) 5/7 . 9/11 + 5/7 + 3/5
   =(5/7 . 9/11) +(5/7 + 3/5 )
   =45/77+46/35
   =371/385
   4) 1/10 – 3/5 -(-1/2)
   =-1/2-(-1/2)
   =0
   5) -5/7 . 9/11 + -5/7 . 2/11 + 1 5/7
   =-5/7 . (9/11+2/11)+1 5/7
   =-5/7 . 1 + 1 5/7
   =-5/7 +12/7
   =7/7=1
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