2x - 17y = 13
Since we don't have the the value of x we would set x = 0
2(0) - 17y = 13
And solve
-17y = 13
y = -13/17
You would do the same if you're solving for x
2x - 17(0) = 13
2x = 13
x = 13/2
(I'm not sure if you are missing anything but based on the information provided this is how I would solve it.)
