Question

factorise (x2_4x)(x2_4x+1)_20​

Answer 1

Solution:

Given (x²-4x)(x²-4x+1)-20

Let x²-4x = a ---(1)

now it becomes,

= a(a+1)-20

=a²+a-20

Splitting the middle term, we get

= a²+5a-4a-20

= a(a+5)-4(a+5)

=(a+5)(a-4)

=(x²-4x+5)(x²-4x-4) /* from (1)*/

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