Please can you verify these answers?

Hi

These following questins are for a maths asignment that I have, could someone please check my answers so that I can make sure Im correct, as I found this question slightly difficult:

http://i213.photobucket.com/albums/c...0697Medium.jpg

My answers:

A) i)

Acceleration= gradient= change in y/change in x

5-2=3 =3x

5u-3u=2u

2u/3= 2/3u

ii)

3x3u= 9u

0.5(5yx3)=7.5u

9u+7.5u= 16.5u

B)

0.5(4x?)=20m

0.5(4x10u)=20m

u=10

Part B is where I was the most unconfident on

Thanks!