1)
(х+36)×10=1130
х+36=1130÷10
х+36=113
х=113-36
х=77
____________
(77+36)×10=1130
1130=1130
2)
21×Х+349=832
21×Х=832-349
21×Х=483
Х=483÷21
Х=23
____________
21×23+349=832
832=832
3)
Х÷12+524=1000
Х÷12=1000-524
Х÷12=476
Х=476×12
Х=5,712
_______________
5,712÷12+524=1000
1000=1000
Вот и все:))))