Вычислите. 2 целых 2/5 - (1/4+7/10) ; 9 целых - (1 целая5/8+3/20) ; 3 целых - (1/6+2/3) ; 4 целых 5/6 - (2 целых3/8+7/12) ; 7 целых - (2 целых3/4+7/12) ; 6 целых 1/4 - (3 целых2/5+3/8)

2 2/5 - (1/4 + 7/10) = 2 8/20 - (5/20 + 14/20) = 1 28/20 - 19/20 = 1 9/20;

9 - (1 5/8 + 3/20) = 9 - (1 25/40 + 6/40) = 8 40/40 - 1 31/40 = 7 9/40;

3 - (1/6 + 2/3) = 3 - (1/6 + 4/6) = 2 6/6 - 5/6 = 2 1/6;

4 5/6 - (2 3/8 + 7/12) = 4 20/24 - (2 9/24 + 14/24) = 3 44/24 - 2 23/24 = 1 21/24 = 1 7/8 (дробь 21/24 сократили на 3) ;

7 - (2 3/4 + 7/12) = 7 - (2 9/12 + 7/12) = 7 - 2 16/12 = 6 12/12 - 3 4/12 = 3 8/12 = 3 2/3 (дробь 8/12 сократили на 4) ;

6 1/4 - (3 2/5 + 3/8) = 6 1/4 - (3 16/40 + 15/40) = 6 10/40 - 3 31/40 = 5 50/40 - 3 31/40 = 2 19/40.