a) 5/7 : (-3/22) - 5/7 : 3/8
= 5/7.(-22/3) - 5/7.8/3
= 5/7.[(-22/3) - 8/3]
= 5/7.(-10)
= -50/7
Vậy 5/7 : (-3/22) - 5/7 : 3/8 = -50/7
b) 5/7 : (1/11 - 5/22) - 5/7 : (1 - 5/8)
= 5/7 : (-3/22) - 5/7 : 3/8
= 5/7.[(-22/3) - 8/3]
= 5/7.(-10)
= -50/7
Vậy 5/7 : (1/11 - 5/22) - 5/7 : (1 - 5/8) = -50/7