Question

How do you graph `y=3x-4`?

Answer 1

Plug in the answer for two `x` values and draw a traight line.
graph{3x-4 [-10, 10, -5, 5]}

You first decide on two `x`'s, say `x=0` and `x=3`
The `y` values belonging to these will be `-4` and `+5`
So you make dots at `(0,-4) and (3,5)` and draw a line

See the picture (you can zoom in or out to get a better understanding)