Question

factorise the following expression

Answer 1

9z²-x²-4y²+4xy,


9z²-(x²+4y²-4xy),


(3z)²-[(x)²+(2y)²-2×x×2y],


(3z)²-(x-2y)²,


[3z+(x-2y)] [3z-(x-2y)]

Answer 2

9z^2 - x^2 - 4y^2 + 4xy

9z^2 - { x^2 + 4y^2 - 4xy }

( 3z )^2 - [ x^2 - 4xy + 4y^2 ]

( 3z )^2 - [ x^2 - 2xy - 2xy + 4y^2 ]

( 3z )^2 - [ x( x - 2y ) - 2y( x - 2y ) ]

( 3z )^2 - [ ( x - 2y )( x - 2y ) ]

( 3z )^2 - ( x - 2y )^2

By Using : a^2 - b^2 = ( a + b )( a - b )

( 3z )^2 - ( x - 2y )

{ ( 3z ) + ( x - 2y ) }{ ( 3z ) - ( x - 2y ) }

{ 3z + x - 2y }{ 3z - x + 2y }

Factorized.