98. Внесите множитель под знак корня:
1) $$ 2\sqrt{7} = \sqrt{2^2 \cdot 7} = \sqrt{4 \cdot 7} = \sqrt{28} $$
2) $$ 3\sqrt{11} = \sqrt{3^2 \cdot 11} = \sqrt{9 \cdot 11} = \sqrt{99} $$
3) $$ 0.2\sqrt{5} = \frac{1}{5}\sqrt{5} = \sqrt{\frac{1}{25} \cdot 5} = \sqrt{\frac{1}{5}} = \sqrt{0.2} $$
4) $$ \frac{1}{3}\sqrt{54} = \sqrt{\frac{1}{9} \cdot 54} = \sqrt{6} $$
5) $$ \frac{3}{5}\sqrt{75} = \sqrt{\frac{9}{25} \cdot 75} = \sqrt{9 \cdot 3} = \sqrt{27} $$
6) $$ -4\sqrt{3} = -\sqrt{16 \cdot 3} = -\sqrt{48} $$
7) $$ -0.1\sqrt{60} = -\frac{1}{10}\sqrt{60} = -\sqrt{\frac{1}{100} \cdot 60} = -\sqrt{\frac{3}{5}} = -\sqrt{0.6} $$
8) $$ 5\sqrt{x} = \sqrt{25x} $$
Ответ: 1) $$\sqrt{28}$$; 2) $$\sqrt{99}$$; 3) $$\sqrt{0.2}$$; 4) $$\sqrt{6}$$; 5) $$\sqrt{27}$$; 6) $$\sqrt{48}$$; 7) $$\sqrt{0.6}$$; 8) $$\sqrt{25x}$$