Question

factorise 27x^3 - 135x^2 + 225x - 125 by using suitable identity​

Answer 1

Answer:

27−125x

3

−135x+225x

2

=(3)

3

−(5x)

3

−3(3)(5x)[3−5x]

=(3−5x)

3

[∵(a−b)

3

=a

3

−b

3

−3ab(a−b)]

Answer 2

27x³ - 135x² + 225 x  - 125

 ( 3 x )³ - 3 ( 9x² ) ( 5 ) + 3 ( 3 x ) ( 25 )  - 5³ 

 ( 3 x )³ - 3 ( 3 x )² ( 5 ) + 3 ( 3 x ) ( 5 )²   - 5³ 

we know that: ( a - b )³ = a³ - 3 a²b + 3 ab² - b³,

So ( 3 x - 5 )³

Hope this helps

Thank you