Simplify each of the following products:

(i)


(ii)


(iii) -x2 + 2x


(iv) (x2 + x – 2) (x2 - x + 2)


(v) (x3 - 3x2x) (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)


= x4x2 + 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


12