8х - 112 = 56
8х = 56 + 112
8х = 168
х = 21
--------------------------
46 - х = 418 : 19
46 - х = 22
х = 46 - 22
х = 24
---------------------------
1287 - 117х = 234
117х = 1287 - 234
117х = 1053
х = 9
---------------------------
85х - 272 = 238
85х = 238 + 272
85х = 510
х = 6
=======================
8(х - 14) = 56
8х - 112 = 56
8х = 56 + 112
8х = 168
х = 21