Distance Formula: Given the two points (x1, y1) and (x2, y2), the distance between these points is given by the formula:

d = ((x2 - x1)^2 + (y2 - y1)^2)^0.5

In our case we have points P(2, −8); Q(−8, 9) that is x1 = 2, x2 = -8, y1= -8, y2 = 9

d = ((-8 - 2)^2 + (9 - (-8))^2)^0.5

d = (100 + 289)^0.5

d = 19.72 approximately

The distance is 19.72 approximately.