1 способ:
56 - (x+12) = 256 - x - 12 = 244 - x = 2-x = -2x = 20
2 способ:
56 - (x+12) = 256 - x - 12 = 2-x = 24 - 56 + 1-x = -2x = 20
Ответ: x = 20.
1 способ:
56 - (x+12) = 2
56 - x - 12 = 2
44 - x = 2
-x = -2
x = 20
2 способ:
56 - (x+12) = 2
56 - x - 12 = 2
-x = 24 - 56 + 1
-x = -2
x = 20
Ответ: x = 20.