А)7 7/9 - 4 1/12 + 2 3/4=5+7/9-1/12+3/4=5+(7*4-1*3+3*9)/36=5+(28-3+27)/36=5+52/36=
6 16/36=6 4/9;
б) 17 2/3 - 6 1/36 + 4 3/8=15+2/3-1/36+3/8=15+(2*24-1*2+3*9)/72=15+(48-2+27)/72=
15 73/72=16 1/72;
в) 10 9/16 - (3 11/12 + 4 4/9)=10 9/16-(7+(33+16)/36)=10 9/16-7 48/36=10 9/16-8 1/3 =
2 9/16-1/3=2 27/48-16/48=2 11/48;
г) (20 - 7 23/36) - (14 4/27 - 6 1/18)=13-23/46-(8 4/27-1/18)=12 23/46-(8 8/54-3/54)=
12 23/46-8 5/54=12 1/2-8 5/54=4 27/54-5/54=4 22/54=4 11/27.