Question

Află numerele a,b și c, stiind că a+b=300, b+c=500, iar a+c=400

Answer 1

a+b=300
b+c=500
a+c=400

2a+2b+2c=300+500+400
2a+2b+2c=1200

a+b+c=1200:2
a+b+c=600

avem relația
a+b+c=600
a+b=300
c=600-300
c=300

avem relația
b+c=500
c=300
b=500-300
b=200

avem relația
a+c=400
c=300
a=400-300
a=100

PROBA :
100+200+300=600

100×2+200×2+300×2=
=200+400+600
=600+600
=1200

100+200=300
200+300=500
100+300=400

Answer 2

a+b=300
b+c=500
a+c=400

a=?
b=?
c=?

2a+2b+2c=300+500+400
2(a+b+c)=1200
a+b+c=1200:2
a+b+c=600

c=600-300
c=300

b=500-300
b=200

a=300-200
a=100

Verificare :
100+200=300
200+300=500
100+300=400

Succes.