Question 92 (xxiv)
Factorise the following using the identity a2−b2=(a+b)(a−b).
y4−81
y4−81=(y2)2−(9)2=(y2+9)(y2−9)=(y2+9)[(y)2−(3)2]=(y2+9)(y+3)(y−3)
Question 92 (xxvi)
(a−b)2−(b−c)2
Question 92 (xix)
x4−1
Question 92 (xxi)
p5−16p
Question 92 (xxii)
16x4−81