Question

Determina numerele a,b,c,știind că:a+b=700, b+c=500, a+c=800.
cum se rezolva?

Answer 1

a+b=700->a=700-b
b+c=500->b=500-c
a+c=800->c=800-a

a=700-(500-800-a)
a=700-(300+a)
a=700+300-a
a=1000-a
2a=1000
a=500.

a+c=800
500+c=800
c=300.

b+c=500
b+300=500
b=200.

Verificare: a+b=500+200=700.
b+c=200+300=500.
a+c=500+300=800.

Sper ca te-am ajutat.

Answer 2

a+b=700,  +
b+c=500,
a+c=800.
----------------
2a+2b+2c=2000
2×(a+b+c)=2000 |÷2
a+b+c=1000

700+c=1000
c=1000-700
c=300

b+300=500
b=200

a+300=800
a=500