1) 6 2/5 * 2 11/12 = (6*5 + 2)/5 * (2*12 + 11)/12 = 32/5 * 35/12 = (32 * 35) / (5 * 12) = [32 и 12 сокращаем на 4, 35 и 5 - на 5] = (8 * 7) / (1 * 3) = 56/3
2) 56/3 - 16 = (56 - 16*3)/3 = (56 - 48)/3 = 8/3
3) 8/3 * (2 1/4) = 8/3 * (2*4 + 1)/4 = 8/3 * 9/4 = (8 * 9) / (3 * 4) = 72 / 12 = 6
Ответ. 6