Squareroot (512 k^2) simplifying radicals.

$$\\\sqrt{512k^2}\\
=\sqrt{4*128}*\sqrt{k^2}\\
=\sqrt{4}*\sqrt{128}*\sqrt{k^2}\\
=\sqrt{4}*\sqrt{4}*\sqrt{32}*\sqrt{k^2}\\
=\sqrt{4}*\sqrt{4}*\sqrt{16}*\sqrt{2}*\sqrt{k^2}\\
=2*2*4*\sqrt{2}*k\\
=16k\sqrt2$$

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