Factors-7
From Homeworkwiki
Factorize :
(i) x 2 - 25
(ii) 9 (x - y) 2 - (x + 2 y) 2
(iii) 48 x 3 - 27 x
(iv) 16 a 4 - b 4
Solution:
(i) x 2 - 25 = x 2 - 5 2 = (x + 5) (x - 5)
(ii) 9 (x - y) 2 - (x + 2 y) 2 = [(3x - 3y) 2 - (x + 2 y) 2 ]
= (3 x - 3 y + x + 2 y) (3 x - 3 y - x - 2 y)
= (4 x - y) (2 x - 5 y)
(iii) 48 x 3 - 27 x = 3 x (16 x 2 - 9)
= 3 x [ (4 x) 2 - (3) 2 ]
= 3 x (4 x + 3) (4 x - 3)
(iv) 16 a 4 - b 4
= (4 a 2 ) 2 - (b 2 ) 2
= (4 a 2 + b 2 ) (4 a 2 - b 2 )
= ( 4 a 2 + b 2 ) ( 2a + b ) ( 2a - b )
