1) 3/8+2/5 = 15/40+16/40 = 31/40
2) 6/25*5/18 = 1/5*1/3 = 1/15
3) 5/9:10/27 = 5/9*27/10 = 1*3/2=3/2=1 1/2
Пошаговое объяснение:
