Vector Equation

The points A(1,0), B(7,2) and C(13,7) are the vertices of a triangle.
The midpoints of the sides BC, CA and AB are L, M and N.
Find the vector equation of the lines AL

I got an answer of (1,0) + λ(3,2.5) by doing:
AL = OA + AL, however the book has an answer of (1,0) + λ(2,1), and i'm not sure how they got that answer.

L is the midpoint of BC. So its coordinate is (10,4.5). The vector AL is thus OL-OA = (9,4.5) = 4.5(2,1) which has direction (2,1).

L is the midpoint of BC. So its coordinate is (10,4.5). The vector AL is thus OL-OA = (9,4.5) = 4.5(2,1) which has direction (2,1).

For the vector equation for BM:
I did the same thing as for AL, which is BM = OM - OB, and i got an answer of (0,1.5) However the book says it should be (0,1)?

And for CN:
I got it as (-3,-2), but the book got it as (3,2) - does the negative make a difference?