сейчас я подумаю
Пошаговое объяснение:
1) 5/9+13/27=(5*3)/(9*3)+ 13/27= 15/27+ 13/27= 28/27= 1 1/27
2) 3/8+5/24= (3*3)/(8*3) + 5/24= 9/24+ 5/24= 14/24=7/12
3 )5/12-13/72= (5*6)/(12*6) - 13/72= 30/72 - 13/72=17/72=17/72
4) 3/5-1/7= (3*7)/(5*7) - 5/(7*5)=21/35 - 5/35= 16/35
5) 5/12+1/60 = (5*5)/(12*5) +1/60= 25/60 +1/60= 26/60= 13/30
6) 9/17-19/68= (9*4)/(17*4) - 19/68= 36/68 - 19/68 =17/68 = 1/4
7) 9/10+4/15= (9*3)/(10*3) + (4*2)/(15*2)= 27/30 +8/30=35/30 = 7/6= 1 1/6
8) 4/15- 11/60= (4*4)/(15*4) - 11/60= 16/60 - 11/60 = 5/60 = 1/12
хм...
а это какой класс?