Question

factorize 9a^2-b^2+4b-4

Answer 1

Hi there!

9a² - b² + 4b - 4

= 9a² - (b² - 4b + 4). [Taking '-' common from the three terms]

= 9a² - [(b)² - (2 x b x 2) + (2)²]

= 9a² - (b - 2)² [As, a² - 2ab + b² = (a - b)²]

= (3a)² - (b - 2)²

= (3a + b - 2)[3a - (b - 2)] [As, (a + b)(a - b) = a² - b²]

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

Cheers!

Answer 2

Hi ,

9a² - b² + 4b - 4

= 9a² - [ b² - 4b +4 ]

= ( 3a )² - [ b² - 2× b× 2 + 2² ]

= ( 3a )² -( b - 2 )²

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

I hope this helps you.

:)