Find the difference between the coords first: x: 6-(-9)=15, y: 5-(-4)=9.
Now add the numbers of the ratio together: 2+1=3 and divide the distances by this : 5 and 3 respectively.
SR is 2/3 along the x distance so that’s ⅔ of 15=10 and 2/3 along the y distance which is ⅔ of 9 which is 6.
So we add 10 to the x-coord of the S to get 10-9=1; and 9 to the y-coord to get 6-4=2.
This gives us R(1,2).
