Question

(x²-4x)(x²-4x-1)-20 ​

Answer 1

$\sf\pink{ answer \: }$

Let (²– 4)= P

=⟩ P(P–1)–20

=⟩ P²–P–20

=⟩P²–5P+4P–20

=⟩P(P−5)+4(P−5)

=⟩(P+4)(P−5)

put P=x²−4x=P

(x²−4x+4)(x²−4x−5)

(x−2)² (x+1)(x−5)

$\sf\large{Here's \: \: \: your \: \: \: answer}$

Answer 2

Step-by-step explanation:

Let (x^2–4x)=p.

= p.(p-1)-20.

= p^2 -p -20.

= p^2 -5p + 4p -20.

= p (p-5 ) + 4 (p - 5 ).

= (p - 5 ) (p + 4 ).

put p = x^2 -4x.

= (x^2 - 4 x - 5 ) (x ^2 -4 x + 4 ).

=[ x^2–5x + x -5 ] ( x - 2 )^2.

=[ x (x- 5) +1( x-5 )].(x-2)^2.

= (x-5) (x + 1) (x - 2 )^2. . Answer.