Răspunsuri

2014-05-13T18:17:11+03:00
A+b+b+c+a+c=12+13+15
2a+2b+2c=40
2(a+b+c)=40
a+b+c=20

c=20-12
c=8

a=20-13
a=7

b=20-15
b=5