С3 первого и второго варианта . все ​

Пошаговое объяснение:

1) 8 3/4 - 7 5/6 = 8 9/12 - 7 10/12 = 7 21/12 - 7 10/12 = 11/12

2) 8 - 2 13/14 - 1 20/21 = 8 - (2 39/42 + 1 40/42) = 8 - 3 79/42 = 8 - 4 37/42 = 3 5/42

3) 10 21/25 - (8 1/5 - 4 7/10) = 10 21/25 - (8 2/10 - 4 7/10) = 10 21/25 - 3 1/2 = 10 42/50 - 3 25/50 = 7 17/50

1) 7 11/15 - 3 9/20 - 1 1/30 = 7 44/60 - 3 27/60 - 1 2/60 = 3 15/60 = 3 1/4

2) 10 - ( 5 4/5 - (8 3/4 - 8 7/15) - 3 5/12) = 7 9/10

по действиям

1) 8 3/4 - 8 7/15 = 8 45/60 - 8 28/60 = 17/60

2) 5 4/5 - 17/60 = 5 48/60 - 17/60 = 5 31/60

3) 5 31/60 - 3 5/12 = 5 31/60 - 3 25/60 = 2 6/60 = 2 1/10

4) 10 - 2 1/10 = 7 9/10