Найдите сумму: б) 2/3 + 3/18 + 5/6 + 7/18

2/3 + 3/18 + 5/6 + 7/18 = (2/3 + 5/6) + (3/18 + 7/18) = (4/6 + 5/6) + 10/18 = 9/6 + 10/18 = 3/2 + 5/9 = 27/18 + 10/18 = 37/18 = 2 1/18