Question

This has to be factorised. Thank you :) ​

Answer 1

Q) Factorise :- (x - y)² - 7(x² - y²) + 12(x + y)²

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Answer :-

(x - y)² - 7(x² - y²) + 12(x + y)²

=> x² + y²- 2xy - 7(x² - y²) + 12(x + y)²

=> - 6x² + 8y²- 2xy + 12x² + 12y² + 24xy

Collecting like terms :-

=> 6x² + 20y² + 20xy

Factorized form :-

6x² + 20y² + 20xy.

Identities used in first step :-

• (a - b)² = a² + b² - 2ab
• (a + b)² = a² + b² + 2ab