Question 418009
x+y=9
x=0,y=9 (0,9)
y=0,x=9 (9,0)
...
x-y=3
x=0,y=-3 (0,-3)
y=0,x=3 (3,0)

{{{drawing(300,300,-10,10,-10,10,circle(0,9,0.2),circle(9,0,0.2),circle(0,-3,0.2),circle(3,0,0.2),graph(300,300,-10,10,-10,10,y=9-x,y=x-3))}}}


The solution is (6,3)