(b+179)-89 = b + 179 - 89 = b + 90
b=56 56 + 90 = 146
b=75 75 + 90 = 165
(839+c)-239 = 839 + c - 239 = c + 600
c=37 37 + 600 = 637
c=98 98 + 600 = 698
(256-x)-156 = 256 - x - 156 = 100 - x
x=44 100 - 44 = 56
х=87 100 - 87 = 13
238-(38+a) = 238 - 38 - a = 200 - a
a=78 200 - 78 = 122
а= 0 200 - 0 = 200