Question

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Answer 1

I think the answer might be a

Answer 2

$\dfrac{6}{10x^2}\div\dfrac{6}{10x^3+60x^2}=\dfrac{6}{10x^2}\cdot\dfrac{10x^3-60x^2}{6}\\\\=\dfrac{1}{10x^2}\cdot\dfrac{10x^2(x-6)}{1}=x-6\to A.$