Linear Relationships
Vertical and Horizontal Lines
Modelling with Linear Relationships
Linear Algebra Skills

The Feasible Region (Fete Stall Series)

All horizontal lines have equations in the form of y=c. The gradient of a horizontal line is zero.
All vertical lines have equations in the form x=a. The gradient of a vertical line is undefined.
All vertical lines have equations in the form x=a. The gradient of a vertical line is undefined.