Răspuns:
Avem un sistem de 3 ecuatii cu 3 necunoscute.
x+y=110
y+z=90
z+x=100
<=>
x=110-y
y+z=90
z+x=100
<=>
y+z=90
z+110-y=100
<=>
y=90-z
z-y=100-110
<=>
y=90-z
z-(90-z)=10
<=>
y=90-z
z-90+z=10
<=>
y=90-z
2z=10+90
<=>
y=90-z
2z=100 |:2
<=>
y=90-z
z=50
<=>
y=90-z=90-50=40
x=110-y=110-40=70
