Thực hiện phép tính: 5/17 - 25/31 + 12/17 + (- 6/21)

c) = 3/4. (11/27 + 16/27)

= 3/4 . 1 = 3/4

d) = (27/23 - 4/23) + 5/21 + 16/21 + 1/2

= 1 + 1 + 1/2 = 2 + 1/2 = 5/2

a) 5/17 - 25/31 + 12/17 + (- 6/21)

= (5/17 + 12/17) - (25/31 + 6/31)

= 1 - 1 = 0

b) 17/8 : (23/8 + -9/2)

= 17/8 : (-13/8)

= -17/13

c)

= 3/4. (11/27 + 16/27)

= 3/4 . 1 = 3/4

d)

= (27/23 - 4/23) + 5/21 + 16/21 + 1/2

= 1 + 1 + 1/2 = 2 + 1/2 = 5/2