Question

aflati a, b, c daca: a+b=34, b+c=39, a+c=27

Answer 1

a+b=34
b+c=39
a+c=27(+)

2(a+b+c)=34+39+27
2(a+b+c)=73+27
2(a+b+c)=100
a+b+c=100:2
a+b+c=50

a+b+c=50
a+b=34
34+c=50
c=50-34
c=16

a+b+c=50
b+c=39
a+39=50
a=50-39
a=11

a+b+c=50
a+c=27
11+b+16=50
27+b=50
b=50-27
b=23

Answer 2

a+b+c=?
a+b=34
b+c=39
a+c=27
a=34-b
34-b+b=34
2b=34
b=34:2
b=17
de aici aplice aceeasi formula