1) х+(24+17)=58
х+58=24+17
х+58=41
х=58-41
х=17
--------------------
17+(24+17)=58
58=58
2)(95-28)-х=47
х=95-28
х=67
х=67-47
х=20
---------------------
(95-28)-20=47
47=47
3) х-(64-28)=81+19
х-(64-28)=100
х=64-28
х=36
х=100+36
х=136
----------------------------
136-(64-28)=81+19
100=100