РЕШЕНИЕ
1) 8 4/9 - х = 3 7/9
х = 8 4/9 - 3 7/9 = 4 2/3
2) (х - 1 8/23) + 3 19/23 = 5 12/23
х = 5 12/23 - 3 19/23 + 1 8/23 = 3 1/23
3) (20 -х) - 6 7/18 = 3 17/18
20 - 3 17/18 - 6 7/18 = х = 9 2/3
4) 1,2 - (х -1/4) = 1/2
х =1 1/5 + 1/4 - 1/2 = 19/20
5) 1,2 - (х+4 7/15) = 5 13/15
х = 1 1/5 - 5 13/15 - 4 7/15 = - 9 2/15