а)
1 способ:
257 - x + 124 = 149
381 - x = 149
-x = 149 - 381
-x = -232
x = 232
2 способ:
257 - x + 124 = 149
-x = 149 - 124 - 257
-x = -232
x = 232
б)
1 способ:
165 - (y + 112) = 37
165 - y - 112 = 37
53 - y = 37
-y = 37 - 53
-y = -16
y = 16
2 способ:
165 - (y + 112) = 37
165 - y - 112 = 37
53 - y = 37
-y = 37 - 53
-y = -16
y = 16
в)
1 способ:
44 + (a - 85) = 105
44 + a - 85 = 105
a - 41 = 105
a = 105 + 41
a = 146
2 способ:
44 + (a - 85) = 105
44 + a - 85 = 105
a - 41 = 105
a = 105 + 41
a = 146