Question

Are the points P(1,2), Q(7,3) and R(-2,1) o the line with vector equation r=(19,5) +s(6,1), SeR

Answer 1

I will do the second point, you do the other two points

for point Q(7,3) to be on r = (19,5) + s(6,1)

7 = 19 + 6s
6s = -12
s = -2

3 = 5 + s
s = -2

Yes, the point Q(7,3) is on the line

(you will have to get the same value of s from both equations for the point to be on the line
that is,
if s = -2
r = (19,5) - 2(6,1)
= (19,5) + (-12, -2)
= (7,3)