Question

Find the value of p so that points with coordinates (3,5),(p,6)& (1/2,15/2) are collinear

Answer 1

Area = 0

3(6-15/2) + p(15/2-5) + 1/2(5-6) = 0

3(12-15÷2) + p(15-10÷2) + 1/2(-1) =0

3(-3/2) + p(5/2) - 1/2 = 0

-9/2 + 5p÷2 - 1/2 = 0

-10/2 = -5p/2

2=P

I'm not sure about this answer...