Question

now, find the change in vertical distance distance from point (2, 9) to point (4, 18), or the change in the length of the scarf after 2 days.
slope = \frac{vertical distance}{horizontal distance}

Explanation:

Step1: Identify vertical values

Vertical values: $y_2=18$, $y_1=9$

Step2: Calculate vertical change

$\Delta y = y_2 - y_1 = 18 - 9$

Answer:

9