Factors-12

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Factorize :

(i) 8a 3 - 27b3

(ii) 2a7 - 128a

Solution :

(i) 8a3 - 27 b3

= (2a)3 - (3b)3

= (2a - 3b)(4a2 + 6ab + 9b2)

(ii) 2a7 - 128a

= 2a(a6 - 64)

= 2a[(a3)2 - (8)2]

= 2a[(a 3 + 8)(a3 - 8)]

= 2a(a3 + 23)(a3- 23)

= 2a(a + 2)(a2 - 2a + 4)(a - 2)(a2 + 2a + 4)

= 2a(a + 2 )(a - 2)(a2 - 2a + 4)(a2 + 2a + 4)

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