Answer:
3
Step-by-step explanation:
We can find the rate of change by picking any two points on the line in the form (x, y) and using the equation below to find the slope (m):
[tex]m = \frac{y_2-y_1}{x_2-x_1}[/tex]
To make things easier, let's pick two points which offer us whole numbers. So: (20, 90) and (0, 30) seem perfect. Plug it into the formula:
[tex]m = \frac{90-30}{20-0} = \frac{60}{20} = 3[/tex]
Thus, the rate of change of the given line is 3.
