Question

How do you graph using the intercepts for `x-y=-3`?

Answer 1

Plot the intercept points and draw a straight line through them:
graph{(x^2+(y-3)^2-0.01)((x+3)^2+y^2-0.01)(x-y+3)=0 [-10, 10, -5, 5]}

Explanation:

x-intercept is the value of `x` when `y=0`
`color(white)("XXX")0-y=-3 rarr y=3`
`rArr` x-intercept is at `(0,3)`

Similarly
`color(white)("XXX")`y-intercept is at `(-3,0)`