Question

Factorise a2-b2-2b-1

Answer 1

7 answers · Mathematics 

 Best Answer

Note that: 

a^2 - b^2 + 2b - 1 

=> a^2 - (b^2 - 2b + 1) 

= a^2 - (b - 1)^2. 

This now factors as a difference of two squares to: 

[a + (b - 1)] * [a - (b - 1)] = (a + b - 1)(a - b + 1). 

Answer 2

Solution :

Given expression:

a² - b² - 2b - 1

= a² - ( b² + 2b + 1 )

= a² - ( b² + 2×b×1 + 1²)

= a² - ( b + 1 )²

= [ a + b + 1 ][ a - ( b + 1 )]

= ( a + b + 1 )( a - b - 1 )

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