So far it looks right.
For the last one, it's something like (2W + ...)(W - ...)
This is what I have done so far but feel it might be wrong.
Factorise the following:
1) Xsquared - Ysquared = (X - Y) (X + Y)
2) (C + D)squared - Dsquared = C (C + 2D)
3) 2Wsquared + W - 3 = how do you do this one again?