Parametric Equations of a Line

I am to find the parametric and vector equations for the line passing through the given points.

P(0, 1/2, 1) Q(2, 1, -3)

The line through the points is parrellel to:

V = rq - rp (q and p are subscripts correponding to points P and Q)

V = < 2-0, 1-1/2, -3-1>

= <2, 1/2, -4>

R= r + Vt

= < 0 , 1/2, 1 > + < 2t , t/2 , -4t >

= < 2t , 1/2 + t/2 , 1-4t >

Parametric equations

x = 2t

y = 1/2 + t/2

z = 1 - 4t

The answer in the book is:

x = 2 + 2t

y = 1 + t/2

z = -3 - 4t

I have done many questions like these and I basically do the same procedure, and I get the correct equations. I don't understand how this particular set of points is different.