Question

a+b=50 b+c=60 a+c=70 Aflati a b si c

Answer 1

adunam toate ecuatiile
a+b+b+c+a+c=50+60+70
2a+2b+2c=180
2(a+b+c)=180 |(×2)
a+b+c=90 (1)
inlocuim pe a+b=50 in (1)

50+c=90
c=90-50
c=40

inlocuim pe b+c =60 in (1)
a+60=90
a=90-60
a=30

inlocuim pe a+c=70 in (1)
b+70=90
b=90-70
b=20
cerificare:
a+b+c=30+20+40=90

Answer 2

a+b+b+c+a+c=50+60+70
2(a+b+c)=180
a+b+c=90
a+b=50=>c=40
b+c=60=>a=30
a+c=70=>b=20