Răspuns :
a + b + c = 820
a + b = 572
c = a - 158
572 + c = 820
c = 820 - 572
c = 248
a = 248 + 158
a = 406
b = 572 - 406
b = 166
a + b = 572
c = a - 158
572 + c = 820
c = 820 - 572
c = 248
a = 248 + 158
a = 406
b = 572 - 406
b = 166
a+b+c=820
a+b =572
a=c+158
572+c=820
c=820-572
c=248
a=248+158
a=406
406+b=572
b=572-406
b=166
verificare:166+248+406=820
a+b =572
a=c+158
572+c=820
c=820-572
c=248
a=248+158
a=406
406+b=572
b=572-406
b=166
verificare:166+248+406=820