Question

25(x+y)^2-36(x-2y)^2

Answer 1

25(x + y)² - 36(x - 2y)²

= [5(x + y)]² - [6(x - 2y)]²

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Using a² - b² = ( a + b) (a - b):

[5(x + y)]² - [6(x - 2y)]²

= [ 5(x + y) + 6(x -2y) ] [ 5(x + y) - 6(x -2y) ]

= ( 5x + 5y + 6x - 12y )( 5x + 5y - 6x + 12y )

= (11x -7y )(17y - x)

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Answer: (11x -7y )(17y - x)