Вычесли и обрати дробь десятичную в обычную 0,2-1/7 , 5/6-0,1 и

0,2 - 1/7 = 2/10 - 1/7 = 2*7/10*7 - 1*10/7*10 = 14/70 - 10/70 = 4/70 = 2/35;
5/6 - 0,1 = 5/6 - 1/10 = 5*10/6*10 - 1*6/10*6 = 50/60 - 6/60 = 50 - 6/60 = 44/60 = 11/15;
0,4 - 2/6 = 4/10 - 2/6 = 4*6/6*10 - 2*10/6*10 = 24/60 - 20/60 = 24 - 20/60 = 4/60 = 1/15