Factorise: a2−b2+2bc−c2
a2−b2+2bc−c2=a2−(b2−2bc+c2)=a2−(b−c)2=(a+b−c)(a−b+c)
Factorise:
a2+b2-2ba+2bc-2ca
a2+2ab+b2−c2
a2+b2−c2−d2+2ab−2cd