А)6 2/5-1 1/10 б)4 5/7 - 1 2/3 в)3 1/2-1 2/3 2)15 1/2-(6 1/4+2 3/8)

6 2/5-1 1/10=6 4/10-1 1/10=5 3/10
4 5/7 - 1 2/3 =4 15/21-1 14/21=3 1/21
3 1/2-1 2/3 = 3 3/6-1 4/6 = 1 5/6
15 1/2-(6 1/4+2 3/8) = 15 4/8 - 6 2/8 -2 3/8=9 2/8 - 2 3/8=6 7/8