a)
$$
6\frac{1}{9} + 10\sqrt{1,96} = \frac{55}{9} + 10 \cdot 1,4 = \frac{55}{9} + 14 = \frac{55 + 14 \cdot 9}{9} = \frac{55 + 126}{9} = \frac{181}{9} = 20 \frac{1}{9}
$$
б)
$$
18 - 4\sqrt{\frac{1}{64}} = 18 - 4 \cdot \frac{1}{8} = 18 - \frac{1}{2} = 17,5
$$
в)
$$
(3\sqrt{2,5})^2 = 9 \cdot 2,5 = 22,5
$$
2. a)
$$
\sqrt{0,36 \cdot 144} = \sqrt{0,36} \cdot \sqrt{144} = 0,6 \cdot 12 = 7,2
$$
б)
$$
\sqrt{54} \cdot \sqrt{24} = \sqrt{54 \cdot 24} = \sqrt{1296} = 36
$$
в)
$$
\frac{\sqrt{72}}{\sqrt{50}} = \sqrt{\frac{72}{50}} = \sqrt{\frac{36}{25}} = \frac{6}{5} = 1,2
$$
г)
$$
\sqrt{36} \cdot 2^4 = 6 \cdot 16 = 96
$$
Ответ: 1. a) $$20 \frac{1}{9}$$, б) 17,5, в) 22,5; 2. а) 7,2, б) 36, в) 1,2, г) 96