Answer
The slope is -2 movies per CD.
Work Step by Step
Find the slope using 2 known points.
If the number of CDs is 0, the number of movies is 20.
If the number of movies is 0, the number of CDs is 10.
The y-axis is the number of movies and the x-axis is the number of CDs.
$slope=\frac{\Delta y}{\Delta x}=\frac{0-20}{10-0}=\frac{-20}{10}=-2$
