Question

2. Tính: A) 1/3 + 1/5 - 1/4. B) 7/8 - ( 1/4 + 2/5 ). C) 5/11 - ( 3/5 - 6/11 ). D) 5/7 - ( 19/35 - 6/15 ).

Answer 1

 `A) 1/3 + 1/5 - 1/4 = 20/60 + 12/60 - 15/60 = 17/60`

 

` B) 7/8 - ( 1/4 + 2/5 ) = 7/8 - 2/4 -2/5 = 5/8-2/8 = 9/40`

 

` C) 5/11 - ( 3/5 - 6/11 ) = 5/11 - 3/55 = 25/55 - 3/55 = 22/55=2/5 ` 

 

` D) 5/7 - ( 19/35 - 6/15 ) = 5/7 - 1/7 = 4/7 `