Question

Find the value of P for which the points (-5,1),(1,p) and (4,-2) are collinear

Answer 1

y2-y1/x2-x1 = y3-y1/x3-x1

(-5,1),(1,p) and (4,-2)

for p=-1 the points (-5,1),(1,p) and (4,-2) are collinear

Answer 2

-5 1

1 p

4 -2

-5 1

(-5p-2+4)-(1+4p+10)

(-5p+2)-(4p+11)

(-5p+2)(-4p-11)

-5p+4p=-11-2

-p=-13

P=13