CÂU 2:Tính giá trị biểu thức

a,(1/8 + -3/4) : 5/6 + 1/2

b,1/2 + 3/4 - ( 3/4 - 4/5 )

c,2/3 + 1/3 × ( -4/9 + 5/6 )

d, 2/5 + 3/5 : ( 3/5 + -2/3 ) - 3 1/2

e, ( 2 - 5/12 ) : 3 + 17/36

f,2/3 + 20% × 10/7

g,(7/8 - 3/4 ) × 1 1/3 - 2/3 × 0,5

h, ( 2+ 5/6 ) : 1 1/5 + -7/12

i,75% - 1 1/2 + 0,5 : 5/12

`a) (1/8 + -3/4) : 5/6 + 1/2`

`= (1/8 - 6/8) : 5/6 + 1/2`

`= (-5/8) : 5/6 + 1/2`

`= (-5/8) × 6/5 + 1/2`

`= -3/4 + 1/2`

`= -3/4 + 2/4`

`= -1/4`

`b) 1/2 + 3/4 - (3/4 - 4/5)`

`= 1/2 + 3/4 - 3/4 + 4/5`

`= 1/2 + 4/5`

`= 5/10 + 8/10`

`= 13/10`

`c) 2/3 + 1/3 × (-4/9 + 5/6)`

`= 2/3 + 1/3 × (-8/18 + 15/18)`

`= 2/3 + 1/3 × 7/18`

`= 2/3 + 7/54`

`= 36/54 + 7/54`

`= 43/54`

`d) 2/5 + 3/5 : (3/5 + -2/3) - 3 1/2`

`= 2/5 + 3/5 : (9/15 - 10/15) - 7/2`

`= 2/5 + 3/5 : (-1/15) - 7/2`

`= 2/5 + 3/5 × (-15) - 7/2`

`= 2/5 - 9 - 7/2`

`= 4/10 - 90/10 - 35/10`

`= -121/10`

`e) (2 - 5/12) : 3 + 17/36`

`= (24/12 - 5/12) : 3 + 17/36`

`= 19/12 : 3 + 17/36`

`= 19/36 + 17/36`

`= 36/36`

`= 1`

`f) 2/3 + 20% × 10/7`

`= 2/3 + 1/5 × 10/7`

`= 2/3 + 2/7`

`= 14/21 + 6/21`

`= 20/21`

`g) (7/8 - 3/4) × 1 1/3 - 2/3 × 0,5`

`= (7/8 - 6/8) × 4/3 - 2/3 × 1/2`

`= 1/8 × 4/3 - 1/3`

`= 1/6 - 1/3`

`= 1/6 - 2/6`

`= -1/6`

`h) (2 + 5/6) : 1 1/5 + -7/12`

`= (12/6 + 5/6) : 6/5 - 7/12`

`= 17/6 : 6/5 - 7/12`

`= 17/6 × 5/6 - 7/12`

`= 85/36 - 7/12`

`= 85/36 - 21/36`

`= 64/36`

`= 16/9`

`i) 75% - 1 1/2 + 0,5 : 5/12`

`= 3/4 - 3/2 + 1/2 : 5/12`

`= 3/4 - 6/4 + 1/2 × 12/5`

`= -3/4 + 6/5`

`= -15/20 + 24/20`

`= 9/20`

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