6 2/5 - ( 2,35 - 1 1/3) +1,02

1) 2,35 - 1 1/3 = 2 35/100  -  1 1/3 = 47/20  -  4/3 = (47 × 3  -  4 × 20)/60 = 141/60  -  80/60 =  61/60 = 1 1/60 2)6 2/5  -  1 1/60 = 32/5  -  61/60 =   (32 × 12  -  61 × 1)/60 = 384/60  -  61/60 =  323/60 = 5 23/60 3)5 23/60  +  1 2/100 = 323/60  +  51/50  =(323 × 5  +  51 × 6)/300 = 1615/300  +  306/300 =  1921/300 = 6 121/300

62/5=12.4-2.35+11/3= -1.2511/3=3.612.4-1.25+1.02=12.17