Make a table of values by arbitrarily choosing a value for x or y,
then substituting it for that letter and solving for the other letter.
I arbitrarily chose x=-6, substituted it and got y=9
I arbitrarily chose y=4, substituted it and got x=-2
I arbitrarily chose x=2, substituted it and got y=-1
I arbitrarily chose y=-6, substituted it and got x=6

I was lucky to have gotten all whole numbers, but even if you aren't
so lucky and get fractins you can guess fractions approximately in between
whole numbers:


 x |  y
-------
-6 |  9
-2 |  4
 2 | -1
 6 | -6

Plot the points (-6,9), (-2,4), (2,-1) and (6,-6)



Then draw a line through them:

Plot the points (-6,9), (-2,4), (2,-1) and (6,-6)



Edwin