1） 4a^2+2a-b-b^2
=(4a^2-b^2)+(2a-b)
=(2a-b)(2a+b)+(2a-b)
=(2a-b)(2a+b+1)
2) 2pq-p^2+1-q^2
=1-(p^2-2pq+q^2)
=1-(p-q)^2
=(1+p-q)(1-p+q)
3) x^2+2xy+y^2-3x-3y+2
=(x+y)^2-3(x+y)+2
=(x+y-1)(x+y-2)