1)
x - 56924 = 7409,
х = 7409 + 56924,
х = 64333,
2)
x + 72315 = 140053,
х = 140053 - 72315,
х = 67738,
3)
610408 - x = 5914,
х = 610408 - 5914,
х = 604494,
4)
93204 - (x + 7958) = 18376,
93204 - х - 7958 = 18376,
х = 93204 - 7958 - 18376,
х = 66870,
или (2 способ):
93204 - (x + 7958) = 18376,
х + 7958 = 93204 - 18376,
х + 7958 = 74828,
х = 74828 - 7958,
х = 66870