Question

${x}^{2} - 6xy - 7 {y}^{2}$
factorise.

Answer 1

${x}^{2} - 6xy - 7y \\ = {x }^{2} + xy - 7xy - 7y \\ = x(x + y) - 7y(x + y) \\ = (x - 7y)(x + y)$

Answer 2

Answer :

x^{2} - 6xy - 7y^{2}

= x^{2} - 7xy + xy - 7y^{2}

= x ( x - 7y ) + y ( x - 7y )

= ( x + y ) ( x - 7y )