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