Answer 1

To find graphical solution, construct the table as follows:

Inequation	Equation	Double Intercept form	Points (x, y)	Region
x + y ≥ 4	x + y = 4	`"x"/4 + "y"/4` = 1	A (4, 0), B (0, 4)	0 + 0 `≱ `4 ∴ 0 `≱ `4 ∴ non-origin side
x – y ≤ 0	2x – y = 0	–	O (0, 0), D (2, 4)	2(0) – 0 ≤ 0 ∴ 0 ≤ 0 ∴ origin side

The shaded portion represents the graphical solution.