The distance formula for 2 points = √((x2-x1)^2 + (y2-y1)^2)
use R for x1 and y1 and use S for x2 and y2.
Distance = √((10- 1)^2 + (3-(-6))^2)
Distance = √(9^2 + 9^2)
Distance = √(81 + 81)
Distance = √162
Distance = 9√2
Distance = 12.7 ( Rounded to nearest tenth)