Răspuns :
a+b+c=154
b=a+18=>a=b-18
b=c-13=>c=b+13
b-18+b+b+13=154
3b=154+18-13
b=159:3
b=53
a=53-18=35
c=53+13=66
b=a+18=>a=b-18
b=c-13=>c=b+13
b-18+b+b+13=154
3b=154+18-13
b=159:3
b=53
a=53-18=35
c=53+13=66
a + b + c = 154
b = 18 + a = c - 13
18 + a = c - 13 => a = c - 13 - 18
a = c - 31
c - 31 + c - 13 + c = 154
3 * c = 154 + 31 + 13
3 * c = 198 => c = 66 => a = 66 - 31 = 35 => b = 66 - 13 = 53
b = 18 + a = c - 13
18 + a = c - 13 => a = c - 13 - 18
a = c - 31
c - 31 + c - 13 + c = 154
3 * c = 154 + 31 + 13
3 * c = 198 => c = 66 => a = 66 - 31 = 35 => b = 66 - 13 = 53