89/10-3 3/10; 1-1/7; 1-1/15; 1-1/12; 1-2/9 вычитани дробей

1)   8 9/10 - 3 3/10 = (89 - 33) / 10 = 56/10 = 5 6/10 (=5,6)
2)   1 - 1/7 = 7/7 -1/7= (7-1)/7 = 6/7
3)   1 - 1/15 = 15/15 - 1/15 = (15-1)/15 = 14/15
4)   1 - 1/12 = 12/12 - 1/12 = 11/12
5)   1 - 2/9 = 9/9 - 2/9 = 7/9