x+5y=7
3x+2y=4
x=7-5y
3(7-5y)+2y=4
21-15y+2y=4
-15y+2y=4-21
-13y=-17
y=-17÷-13
y=17/13
x=7-5×17/13
x=6/13
(x;y)=(6/13;17/13)
x+5y=7
3x+2y=4
x=7-5y
3x+2y=4
3(7-5y)+2y=4
21-15y+2y=4
-15y+2y=4-21
-13y=-17
y=-17÷-13
y=17/13
x=7-5×17/13
x=6/13
(x;y)=(6/13;17/13)