(i) x^2-1-2a-a^2 (ii) 1+2ab-(a^2+b^2)
Solution: (i) Given x²-1-2a-a²
=x²-(1+2a+a²)
=x²-(a²+2a+1)
=x²-(a+1)²
=[x-(a+1)][x+(a+1)]
=(x-1-a)(x+1+a)
(ii) Given 1+2ab-(a²+b²)
= 1+2ab-a²-b²
=1-a²-b²+2ab
=1-(a²+b²-2ab)
=(1)²-(a-b)²
=[1-(a-b)][1+(a-b)]
==(1-a+b)(1+a-b)
