Question

$64x {}^{2} + \frac{y {}^{2} }{25}$

Answer 1

$64 {x}^{2} + \frac{ {y}^{2} }{25} \\ \\ = {(8x)}^{2} + { (\frac{y}{5}) }^{2} \\ \\ = (8x - \frac{y}{5} )(8x + \frac{y}{5} )$

Using identity ( a^2 - b^2) = (a + b) (a-b)