Răspuns :
a+b=40+
b+c=30
a+c=30
_______
2a+2b+2c=100/÷2
a+b+c=50
40+c=50
c=10
a+30=50
a=20
30+b=50
b=20
b+c=30
a+c=30
_______
2a+2b+2c=100/÷2
a+b+c=50
40+c=50
c=10
a+30=50
a=20
30+b=50
b=20
a+b =40
b+c=30
a + c=30
---------------
2a+2b+2c=100
2(a+b+c)=100
a+b+c=50
SPER CA TE-AM AJUTAT
b+c=30
a + c=30
---------------
2a+2b+2c=100
2(a+b+c)=100
a+b+c=50
SPER CA TE-AM AJUTAT