Răspuns :
(a+b+c):3=?
(a+b):2=11
(a+c):2=36
(b+c):2=32
(a+b)=11x2=22
a+c=72
b+c=64
2a+2b+2c=92+64=56
56:2=28
28:3=
(a+b):2=11
(a+c):2=36
(b+c):2=32
(a+b)=11x2=22
a+c=72
b+c=64
2a+2b+2c=92+64=56
56:2=28
28:3=
(a+b):2=11; a+b=11x2=22
(b+c):2=36; b+c=36x2=72
(a+c):2=32; a+c=32x2=64
a+b+b+c+a+c=22+72+64=158/:2
a+b+c=79
c=79-22=57
a=79-72=7
b=79-64=15
