Factor polynomial $$ 20a^{2}-45 $$
Answer
$$ 20a^{2}-45 = 5( 2a-3 )( 2a+3 ) $$
Explanation
Step 1 :
After factoring out $ 5 $ we have:
$$ 20a^{2}-45 = 5 ( 4a^{2}-9 ) $$Step 2 :
Rewrite $ 4a^{2}-9 $ as:
$$ 4a^{2}-9 = (2a)^2 - (3)^2 $$Now we can apply the difference of squares formula.
$$ I^2 - II^2 = (I - II)(I + II) $$After putting $ I = 2a $ and $ II = 3 $ , we have:
$$ 4a^{2}-9 = (2a)^2 - (3)^2 = ( 2a-3 ) ( 2a+3 ) $$This page was created using
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