... :5,02,1 17 2 2 4 1 3 9 5 6 7 4 : 25 2 08, 1 25 1 64,0 25,1 5 4 :8, 0 ×+ × − − + − × ( ) 3 1 2 4 3 4 1 6 8 4 3 7 4 7 1 6,0 8, 0 5 4 :6,0 17 36 36 119 7 4 : 08, 0 08, 1 ... : − ×− + +× − )15,25 57, 28( :84 ,6 4 )81 ,3306,34( )2, 18, 0(5,2 )1,02,0(:3 + 3 2 : 21 4 Bài làm 2 1 7 2 7 13 2 26 2 7 2 13 :26 2 7 2 1 5 30 :26 2 7 42,3 :84 ,6 425,0 25,2 1,0:3 :26 =+×=+=+ ... tính bằng cách hợp lí a) 14 17 9 4 7 5 18 17 125 11 ++−− b) 1 2 1 2 3 1 3 4 1 4 4 3 3 3 2 2 2 1 1 −−−−−−+−+−+− Bài làm. 1 a) 125 11 2 1 2 1 125 11 9 4 18 17 7 5 14 17 125 11 =−+= −−...