Find the ratio in which the point P(– 1, y) lying on the line segment joining points A(– 3, 10) and B(6, – 8) divides it. Also, find the value of y.
– 1 = (m1x2 + m2x1)/ m1 + m2
– 1 = (m16 + m2(– 3))/ m1 + m2
– 1 = (6m1 – 3m2)/ m1 + m2
(6m1 – 3m2) = – m1 – m2
7m1 = 2 m2
m1: m2 = 2:7
y = (m1y2 + m2y1)/ m1 + m2
= (2x(– 8) + 7 × 10)/9
= (– 16 + 70)/9
= 54 / 9
y = 6