Question

Explain what the graph of x – 4y < 16 would look like.

Answer 1

First think of x-4y=16
the graph should be something like this..

Answer 2

now put x=0 and y=0.. i.e the origin
this satisfies your eqn

Answer 3

graphically the solution will be the side of the line containing origin

Answer 4

think of it like this x-4y=s
now put x=0, y=-4 .. this would just satisfy the line..
next think of x=0 y=-3.9999999, then s<16 ..and so your condition is satisfied!!

Bingo.. check for other combi of x,y ..it is bound to lie in the origin containing region