Răspuns :
notam nr cu x si y.
x+y=30 |•(-2)
2x+5y=114
-2x-2y=-60
2x+5y=114
x+y=30
3y=54
y=54/3=18
x=30-18=12
x+y=30 |•(-2)
2x+5y=114
-2x-2y=-60
2x+5y=114
x+y=30
3y=54
y=54/3=18
x=30-18=12