Bài 1) a) -1/2 – 3/4 + 1/12 b) -16/15 × 3/8 + 3/8 × 1/15 + 11/8 c) (3/4 – 1)² + (1,5 – 1/4) : |-4/5|

1 bình luận về “Bài 1) a) -1/2 – 3/4 + 1/12 b) -16/15 × 3/8 + 3/8 × 1/15 + 11/8 c) (3/4 – 1)² + (1,5 – 1/4) : |-4/5|”

1. Bài 1:

   a) (-1)/2 – 3/4 + 1/12

   = (-5)/4 + 1/12

   = (-7)/6

   b) (-16)/15 . 3/8 + 3/8 . 1/15 + 11/8

   = 3/8 . ( (-16)/15 + 1/15 ) + 11/8

   = 3/8 . (-1) + 11/8

   = (-3)/8 + 11/8

   = 1

   c) ( 3/4 – 1 )^2 + ( 1,5 – 1,4 ) : |(-4)/5|

   = ( (-1)/4 )^2 + 0,1 : 4/5

   = 1/16 + 1/10 : 4/5

   = 1/16 + 1/8

   = 3/16

   Bài 2:

   a) 3/7 – x = 1/3

                      x = 3/7 – 1/3

                      x = 2/21

   Vậy x = 2/21

   b) (-5)/8 + x = ( (-2)/3 )^2

         (-5)/8 + x = 4/9

                          x = 4/9 – (-5)/8

                          x = 77/72

   Vậy x = 77/72

   c) 3/4 + 1/4 : x = -2 1/2

         3/4 + 1/4 : x = (-5)/2

                       1/4 : x = (-5)/2 – 3/4

                       1/4 : x = (-13)/4

                                   x = 1/4 : (-13)/4

                                   x = (-1)/13

   Vậy x = (-1)/13

   Halary08

    

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