2. Найдите значение выражения: 1) $$0,8 \sqrt{400} + \frac{1}{7}\sqrt{49};$$ 3) $$\sqrt{3^{5} \cdot 2^{1}};$$ 2) $$\sqrt{0,36} \cdot 16;$$ 4) $$\sqrt{27} \cdot \sqrt{3} - \sqrt{\frac{28}{7}}$$

<p><strong>1)</strong> $$0,8 \sqrt{400} + \frac{1}{7}\sqrt{49} = 0,8 \cdot 20 + \frac{1}{7} \cdot 7 = 16 + 1 = 17$$</p> <p><strong>2)</strong> $$\sqrt{0,36} \cdot 16 = 0,6 \cdot 16 = 9,6$$</p> <p><strong>3)</strong> $$\sqrt{3^{5} \cdot 2^{1}} = \sqrt{3^{4} \cdot 3 \cdot 2} = \sqrt{81 \cdot 6} = 9\sqrt{6}$$</p> <p><strong>4)</strong> $$\sqrt{27} \cdot \sqrt{3} - \sqrt{\frac{28}{7}} = \sqrt{81} - \sqrt{4} = 9 - 2 = 7$$</p>