Graph 1:
x variable: Number of pounds
y variable: Total cost
Graph 2:
x variable: Area painted
y variable: Amount of paint in can
Graph 3:
x variable: Time
y variable: Grass height
How to name variables on graph?
A graph is a diagram showing the relationship between two or more quantities, measurements or indicative numbers that may or may not have a specific mathematical formula relating them to each other.
Therefore,
The x-axis is the horizontal axis
The y-axis is the vertical axis