Question

factorise the following expressions using suitable identities

$5x {}^{2} - 7y {}^{2}$
​

Answer 1

Answer:

$5 {x}^{2} - 7 {y}^{2} \\ \\ (\sqrt{5}{x})^{2} - (\sqrt{7}{y})^{2} \\ \\ = (\sqrt{5} x + \sqrt{7} y)( \sqrt{5}x - \sqrt{7} y) \\ \\ we \: know \: that \: \\ {x}^{2} - {y}^{2} = (x + y)(x - y)$

Here's The Answer My Friend....