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afla numerele a b c stiind ca sunt verifivate simultan conditiilea+b=12 b+c=13 a+c =15

Răspuns :

a+b=12
b+c=13
a+c=15
2a+2b+2c=12+13+15
2a+2b+2c=40
a+b+c=20
12+c=20
c=8
a+13=20
a=7
7+b+8=20
b=5
Verificare: 7+5+8=20