Question

(x^2 – 3x)^2 - 38(x^2 – 3x) – 80; FACTORISATION​

Answer 1

Step-by-step explanation:

( x² - 3x )² - 38( x² - 3x ) - 80

Substituting k = x² - 3x

= k² - 38k - 80

= k² - 40k + 2k - 80

= k( k - 40 ) + 2( k - 40 )

= ( k + 2 )( k - 40 )

= ( x² - 3x + 2 )( x² - 3x - 40 )

= ( x² - 2x - x + 2 )( x² - 8x + 5x - 40 )

= { x( x - 2 ) - 1( x - 2 ) }{ x( x - 8 ) + 5( x - 8 ) }

= ( x - 1 )( x - 2 )( x + 5 )( x - 8 )

Hence the given expression is factorised.