Question

factories casing identity
50/y² - 2y²/81​

Answer 1

$\begin{gathered} = \frac{50}{ {y}^{2} } - \frac{ {2y}^{2} }{81} \\ = 2( \frac{25}{ {y}^{2} } - \frac{ {y}^{2} }{81} ) \\ = 2 ( \frac{ {5}^{2} }{ {y}^{2} } - \frac{ {y}^{2} }{ {9}^{2} } ) \\ = 2 ({( \frac{5}{y}) }^{2} - ({ \frac{y}{9} }^{2} )) \\ = 2( \frac{5}{y} + \frac{y}{9} )( \frac{5}{y} - \frac{y}{9} )\end{gathered}$