Răspuns :
a = 15 - b
c = 21 - b
si le inlocuim in prima ecuatie
15 - b + b + 21 - b = 26
- b = - 36 + 26
b = 10
a = 15 - 10
a = 5
c = 21 - 10
c = 11
c = 21 - b
si le inlocuim in prima ecuatie
15 - b + b + 21 - b = 26
- b = - 36 + 26
b = 10
a = 15 - 10
a = 5
c = 21 - 10
c = 11
a=15-b
c=21-b
15-b +b + 21-b = 26
15+21 - b = 26
36-26 = b
b= 10
a= 5
c=11
c=21-b
15-b +b + 21-b = 26
15+21 - b = 26
36-26 = b
b= 10
a= 5
c=11