вычислите 2 5/6+4/15+2 1/6*4/15

А НЕ 3 61/90

2 5/6 + 4/15 + 2 1/6 * 4/15 = 17/6 + 4/15 + 13/6 * 4/15 = 17"6 + 4/15 + 13/3 * 2/15 = 17/6 + 4/15 + 26/45 = 331/90 331/90 или 3 61/90