Question 268316
okay, so basically this is a system of linear equations.

{y=3x
{x=3y

and you have to come up with a solution (a coordinate) that works for both equations.
so you can substitute the first equation into the second equation.

so, x=3(3x).......  Use Distributive Property
 ...   x=9x   .......  Subtract x from both sides 
 ...   0=8x   .......  Divide 8 by both sides to isolate x
 ...   0=x
    
okay, now plug in x=0 into the first equation
 ...   y=3(0) .......  Use Distributive Property
 ...   y=0

Now that you have solved for x and y, you have finally found your coordinate (x,y): x=0 and y=0, so your coordinate and solution to this problem is (0,0)