Răspuns :
x+y=390
x+(x+y)=607
x+y=390
2x+y=607
x=390-y
2*(390-y) +y=607
780-2y +y =607
780-607=y
y= 173
x+y=390
x+173=390
x=390-173
x= 217
x+(x+y)=607
x+y=390
2x+y=607
x=390-y
2*(390-y) +y=607
780-2y +y =607
780-607=y
y= 173
x+y=390
x+173=390
x=390-173
x= 217