(-0.4x^2/0.5y^3)^2 simplify the expression using the quotient to a power property

$$\left(\frac{-0.4x^2}{0.5y^3}\right)^2 \\\\
=\left(\frac{-4\times 2 x^2}{10\times y^3}\right)^2 \\\\
=\left(\frac{-4 x^2}{5\times y^3}\right)^2 \\\\
=\frac{16 x^4}{25y^6} \\\\$$

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