Răspuns :
a + b + c = 800
a = 580
b+ c = 800 - 580
b+c = 220
b-- c = 70 => b = c+70
Acum inlocuim.
c + 70 + c = 220
2 c = 220 - 70
2c = 150
c = 150 : 2
c = 75
b = 75 + 70
b = 145
Verificare : 580 + 75 + 145 = 580 + 220 = 800 .
a = 580
b+ c = 800 - 580
b+c = 220
b-- c = 70 => b = c+70
Acum inlocuim.
c + 70 + c = 220
2 c = 220 - 70
2c = 150
c = 150 : 2
c = 75
b = 75 + 70
b = 145
Verificare : 580 + 75 + 145 = 580 + 220 = 800 .