решите пример
4 целых 2/3 - 5/9 * 2 целых 4/7
---------------------------------------------- + 0,8 * 1,25
(2 целых 1/7 + 1 целых 2/3) :5

[4 2/3 - 5/9 * 2 4/7] / [(2 1/7 + 1 2/3) : 5] + 0,8 * 1,25 = 5 целых 1/41) 5/9 * 2 4/7 = 5/9 * 18/7 = (5*2)/(1*7) = 10/7 = 1 3/72) 4 2/3 - 1 3/7 = 4 14/21 - 1 9/21 = 3 5/213) 2 1/7 + 1 2/3 = 2 3/21 + 1 14/21 = 3 17/214) 3 17/21 : 5 = 80/21 * 1/5 = (16*1)/(21*1) = 16/215) 3 5/21 : 16/21 = 68/21 * 21/16 = 68/16 = 17/4 = 4 1/4 6) 0,8 * 1,25 = 17) 4 1/4 + 1 = 5 1/4