Răspuns :
Calcule:
a + b + c = 408
a = b - 2
c = b + 2
b - 2 + b + b + 2 = 408
3b = 408
b = 408 \ 3
b = 136
a = b - 2 = 136 - 2 = 134
c = b + 2 = 136 + 2 = 138
a + b + c = 408
a = b - 2
c = b + 2
b - 2 + b + b + 2 = 408
3b = 408
b = 408 \ 3
b = 136
a = b - 2 = 136 - 2 = 134
c = b + 2 = 136 + 2 = 138
a+a+2+a+4=408
3a+2+4=408
3a+6=408
3a=408-6
3a=402
a=402:3
a=134
a+2=134+2=136
a-4=134+4=138