Factorise by grouping method:
x2+y2+x+y+2xy
Factorise :
(i) 2a3−50a(ii)54a2b2−6(iii) 64a2b−144b3(iv) (2x−y)3−(2x−y)(v) x2−2xy+y2−z2(vi) x2−y2−2yz−z2(vii) 7a5−567a(viii) 5x2−20x49