Question

The mid-point P of the line segment joining the points A(-10,4) and B(-2,0) lies on the line segment joining the points C(-9,-4) and D(-4,y). Find the ratio in which P divides CD. also find the value of y.

Answer 1

first of all you find midpoint p={(-10-2)/2, (4+0)/2}=(-6,2)
now use section formula let ratio R
x=(Rx2+x1)/(R+1)
-6=(-4R-9)/(R+1)
-6R-6=-4R-9
-2R=-3
R=3/2
hence ratio is 3:2
now
2=(3/2y-4)/(3/2+1)
5=3/2y-4
9=3/2y
y=6

Answer 2

this is the answer which is present in the above pic