Verified answer

12 7/12- 4 5/12 - (20 3/4- 19 3/4) = 8 2/12 - 1=7 2/12=7 1/6

точно не знаю правильно или нет))

Verified answer

12  7/12 - 4  5/12 - ( 20 3/4-19 3/4) = 7  1/6

1) 20 3/4 - 19 3/4 = 1

2) 12 7/12 - 4 5/12 = 8 2/12

3) 8 2/12 - 1= 7  2/12 = 7 целых 1/6