Final answer:
The slope of line PQ is -0.4.
Step-by-step explanation:
To find the slope of the line PQ, we need to calculate the difference in the y-coordinates divided by the difference in the x-coordinates of the two points.
The coordinates of P and Q are (0,0) and (-20,8) respectively.
Slope = (change in y-coordinates)/(change in x-coordinates) = (8-0)/(-20-0) = 8/-20 = -0.4
So, the slope of line PQ is -0.4.