Question

How do you graph the equation `x=10-y`?

Answer 1

Plot a couple sample points and draw a line through those points.

Explanation:

If we recognize `x=10-y` as a linear equation,
then we know we only need 2 sample points.
Probably the easiest points to use are the `x` and `y` intercepts
With `x=0` we have `y=10` (the y-intercept)
and
with `y=0` we have `x=10` (the x-intercept)

Plotting those two coordinate pairs on the Cartesian plane and drawing a line through them should give a graph like:
graph{(x^2+(y-10)^2-0.1)((x-10)^2+y^2-0.1)(x+y-10)=0 [-10.7, 25.35, -5.1, 12.91]}