Răspuns :
a+b+c = 154
b = a+18
c = b+13, c = a+18+13, c = a+31
a+a+18+a+31 = 154
3a = 154-(18+31)
3a = 154 - 49
3a = 105
a = 105:3
a = 35
b = a+18
b = 35+18
b = 53
c = b+13
c = 53+13
c = 66
V: 35+53+66 = 88+66 = 154
b = a+18
c = b+13, c = a+18+13, c = a+31
a+a+18+a+31 = 154
3a = 154-(18+31)
3a = 154 - 49
3a = 105
a = 105:3
a = 35
b = a+18
b = 35+18
b = 53
c = b+13
c = 53+13
c = 66
V: 35+53+66 = 88+66 = 154
a+b+c=154.
b=18+a
b=13-c
a+18+a+c=154
2a+18+c=154
2a+c= 154-18
2a+c= 136
a+c = 136:2
a+c= 68
b= 13-c = 68-13
b= 55
a+b+c=154
a+c=68 si b= 55
68+55=123
154-123= 31
c=31
a=68, b=55, c+31
68+55+31=154
b=18+a
b=13-c
a+18+a+c=154
2a+18+c=154
2a+c= 154-18
2a+c= 136
a+c = 136:2
a+c= 68
b= 13-c = 68-13
b= 55
a+b+c=154
a+c=68 si b= 55
68+55=123
154-123= 31
c=31
a=68, b=55, c+31
68+55+31=154