Question 92 (xxviii)
Factorise the following using the identity a2−b2=(a+b)(a−b).
x4−y4+x2−y2
x4−y4+x2−y2=(x2)2−(y2)2+(x2−y2)=(x2+y2)(x2−y2)+(x2−y2)=(x2−y2)(x2+y2+1)=(x+y)(x−y)(x2+y2+1)
Question 92 (viii)
x29−y225
Question 92 (xiii)
x28−y218
Question 92 (xx)
y4−625
Question 92 (xix)
x4−1