Simplify each of the following products:
(i)
(ii)
(iii) -x2 + 2x
(iv) (x2 + x – 2) (x2 - x + 2)
(v) (x3 - 3x2 – x) (x2 - 3x + 1)
(vi) (2x4 - 4x2 + 1) (2x4 - 4x2 - 1)
(i) On regarranging we get,
(ii) On regarranging we get,
(iii) On rearranging we get, -x2 + 2x
=
Using, (a-b)2 = a2 + b2 – 2ab
(iv) Using the idendity, (a+b)(a-b) = a2-b2
On rearranging we get,
(x2 + x – 2) (x2 - x + 2) = {x2 + (x – 2)} {(x2 – (x - 2)}
= (x2)2 – (x – 2)2 = x4-(x2 - 4x + 4)
= x4 – x2 + 4x – 4
(v) Taking x as common factor, we write,
= x (x2 - 3x – 1) (x2 - 3x + 1)
= {x (x2 - 3x – 1)} (x2 - 3x + 1)
= x [{(x2 - 3x) – 1)} {(x2 - 3x)+1)}]
= x {(x2 - 3x)2 – 12}
= x (x4 - 6x3+9x2-1)
= x5 – 6x4 + 9x3 -x
(vi) On Reaaranging we get,
(2x4 - 4x2 + 1) (2x4 - 4x2 - 1)
= {(2x4 - 4x2) + 1} {(2x4 - 4x2)- 1)}
= (2x4 - 4x2)2 – 12
= 4x8 + 16x4 -2 × 2x4 × 4x2 – 1
= 4x8 + 16x4 -16x6 -1