Simplify:
(i) 
(ii) 
(iii) 
(iv) 
(v) 
(i) 
(x2 – y2) (x2 + y2) (x4 + y4)
= [(x2)2 – (y2)2] (x4 + y4)
= (x4 – y4) (x4 – y4)
= [(x4)2 – (y4)2]
= x8 – y8
(ii) 
[(2x)2 – (1)2] (4x2 + 1) (16x4 + 1)
= (4x2 – 1) (4x2 + 1) (16x4 + 1) 1
= [(4x2)2 – (1)2] (16x4 + 1) 1
= (16x4 – 1) (16x4 + 1) 1
= [(16x4)2 – (1)2] 1
= 256x8 – 1
(iii) 
(7m)2 + (8n)2 – 112mn + (7m)2 + (8n)2 + 112mn
= 49m2 + 64n2 + 49m2 + 64n2
= 98m2 + 64n2 + 64n2
= 98m2 + 128n2
(iv) 
(2.5p)2 + (1.5q)2 – 2 (2.5p) (1.5q) – (1.5p)2 – (2.5q)2 + 2 (1.5p) (2.5q)
= 6.25p2 + 2.25q2 – 2.25p2 – 6.25q2
= 4p2 – 6.25q2 + 2.25q2
= 4p2 – 4q2
= 4 (p2 – q2)
(v) 
(m2)2 – 2 (m2) (n2) (m) + (n2m)2 + 2m3n2
= m4 – 2m3n2 + (n2m)2 + 2m3n2
= m4 + n4m2 – 2m3n2 + 2m3n2
= m4 + m2n4
= m2 (m2 + n4)
19