Вычислите удобном х15 12/13-3 1/3х6 12/13

11 5/7 * 4 4/11 - 4 4/11 * 6 5/7 = 4 4/11 * (11 5/7 - 6 5/7) = 4 4/11 * 5 = 
= (4 * 5) + (4/11 * 5) = 20 20/11 = 21 9/11

3 1/3 * 15 12/13 - 3 1/3 * 6 12/13 = 3 1/3 * (15 12/13 - 6 12/13) =
= 3 1/3 * 9 = (3 * 9) + (1/3 * 9)= 27 9/3 = 30