Question

Aflati trei numere naturale a,b,c care verifica simultan relațiile : a+b=28,b+c=16,c+a=20

Answer 1

a=20-c

b=16-c

a+b=28 asadar 20-c+16-c=28

-2c=28-36

-2c=-12

c=6 deci a=14 b=10

Answer 2

a+b=28

a+c=20 le scad si voi obtine

b-c=8

Acum am

b+c=16

b-c=8 le adun si voi obtine

2b=24=>b=24:2=>b=12

Acum am b=12 si b+c=16=> c=4

Acum am c=4 si a+c=20=> a=16

Acum am a=16 si a+b=28=> b=12