Question

Find the value of p for which the points A(3,1) B (5,p) and C (7,-5) are collinear

Answer 1

Answer:

eqn of line is y-1=m(x-3)

m=(1+5)/(3-7)=-6/4=-3/2

hence eqn is y-1=-1.5(x-3)

(5,p) lies on this line

hence p-1=-1.5*2

p=-3+1=-2