Выполните действия:а)2/7:3 б)2 6/7:1 8/9
А) 2/7 : 3 = 2 : (7*3) = 2/21 б) 2 6/7 : 1 8/9 = 20/7 : 17/9 = (20*9)/ (7*17) = 180/119 = 1 61/119
А) (2/7):3= =2/21 б)2 6/7:1 8/9= =(14+6)/7:(9+8)/9= =20/7:17/9= =20/7×9/17= =180/119= =1 61/119