Factor polynomial $$ 4x^{2}-81y^{2} $$
Answer
$$ 4x^{2}-81y^{2} = (2x+9y)(2x-9y) $$
Explanation
Rewrite $ 4x^2-81y^2 $ as:
$$ \color{blue}{ 4x^2-81y^2 = (2x)^2 - (9y)^2 } $$Now we can apply the difference of squares formula.
$$ I^2 - II^2 = (I - II)(I + II) $$After putting $ I = 2x $ and $ II = 9y $ , we have:
$$ 4x^2-81y^2 = (2x)^2 - (9y)^2 = ( 2x-9y ) ( 2x+9y ) $$This page was created using
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