выполните действие а)1/7+4/21 б)4/5-7/10 в)2 5/6-1 2/3 г)3 1/2+3/8

1/7 + 4/21 = 3/21 + 4/21 = 7/21 = 1/3,

4/5 - 7/10 = 8/10 - 7/10 = 1/10,

2 5/6 - 1 2/3 = 2 5/6 - 1 4/6 = 1 1/6,

3 1/2 + 3/8 = 3 4/8 + 3/8 = 3 7/8

a)7/21 б) 15/10= 1,5 в) 1 1/6 г) 6 7/8