4n(5n+3)^2-n(10n+1)^2

Question

4n(5n+3)^2-n(10n+1)^2

Answer 1

80=16*5=4²*5
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80^n/(4^2n-1*5^n-2)=4^2n*5^n/(4^2n-1*5^n-2)=4*5²=4*25=100