\(=\left(15\cdot10\sqrt{2}-4\cdot15\sqrt{2}+2\cdot5\sqrt{2}\right)\cdot\sqrt{\dfrac{1}{10}}-10\cdot2\cdot\sqrt{5}\)
\(=\dfrac{100\sqrt{2}}{\sqrt{10}}-20\sqrt{5}\)
\(=20\sqrt{5}-20\sqrt{5}=0\)
\(\left(15\sqrt{200}-4\sqrt{450}+2\sqrt{50}\right)\sqrt{\dfrac{1}{10}}-10\sqrt{20}\)
\(=\left(15\sqrt{10^2.2}-4\sqrt{15^2.2}+2\sqrt{5^2.2}\right)\sqrt{\dfrac{1}{10}}-10\sqrt{2^2.5}\)
\(=\left(15.10\sqrt{2}-4.15\sqrt{2}+2.5\sqrt{2}\right)\sqrt{\dfrac{1}{10}}-10.2\sqrt{5}\)
\(=100\sqrt{2}.\sqrt{\dfrac{1}{10}}-20\sqrt{5}\)
\(=20.\sqrt{25}.\sqrt{2}.\sqrt{\dfrac{1}{10}}-20\sqrt{5}\)
\(=20.\sqrt{25.2.\dfrac{1}{10}}-20\sqrt{5}\)
\(=20\sqrt{5}-20\sqrt{5}=0\)
