Draw the graph of `x - 2y ge 4`.

Explanation

(a) We first draw `x-2y=4`.
`{:(x,,0,,2,,4),(y,,-2,,-1,,0):}`
Some of the ordered pairs of `x-2y = 4` are `(0, -2), (2, -1), (4, 0)`.

(b) Substitute (0, 0) in `x - 2y ge 4`.
`rArr 0 - 2(0) ge 4`.
`rArr 0-2 (0) ge 4`.
`rArr 0 ge 4`, which is false.
`therefore (0, 0)` does not belong to the graph represented by `x - 2y ge 4`.
(c) Now shade the region (half plane) which does not contain the origin.
We see that the graph of a linear in equation in two variables is a half plane.