Question

$4x {}^{2} - 81y {}^{2}$
​

Answer 1

$\huge\boxed{\underline{\bf\green{A} \: \red{N} \: \orange{S} \: \purple{W} \: \blue{E} \: \pink{R}}}$

$\large\longrightarrow \sf {4x}^{2} - {81y}^{2} \\ \\\large\longrightarrow \sf {(2x)}^{2} - {(9y)}^{2} \\ \\ \large\longrightarrow \sf(2x + 9y)(2x - 9y)$

Identify Used :-

$\large\longrightarrow \sf {a}^{2} - {b}^{2} = (a + b)(a - b)$