Question

How do you graph `y - 4 < x - 6`?

Answer 1

First of all, let's study where the equation holds: you have
`y-4=x-6 \iff y=x-2`.
This is the equation of a line, which you can easily graph. If you think about it, the graph of a function is the set of the points which satisfy the relation `y=f(x)`; but we are looking for the points which satisfy the relation `y < f(x)`.

You can see that the two requests are strongly related: if the graph of the line is the set of points in which `y=x-2` holds, the set of points in which `y< x-2` holds is the part of the plan below the graph, as you can see:

graph{y< x-2 [-10, 10, -5, 5]}