stiind ca: a+b=100, b+c=110, a+c=90 calculeaza:a,b,c

Răspuns :

a)a=100-b
c=110-b
a+c=90⇒100-b+110-b=90
-2b+210=90
-2b=-210+90
-2b=-120    (-1)
b=120/2
b=60
a=100-b=100-60=40
Δc=110-b=110-60=50