71. Найдите значение выражения: 1) 0,2√400 - (1/3)√81; 2) √49 · √0,09 + √2³ + 1; 3) 5√0,64 - √5² + 12²; 4) √(5 4/9) - √(1 11/25) + 0,07√10000.

1.

\(0.2 \cdot \sqrt{400} - \frac{1}{3} \cdot \sqrt{81} = 0.2 \cdot 20 - \frac{1}{3} \cdot 9 = 4 - 3 = 1\)

2.

\(\sqrt{49} \cdot \sqrt{0.09} + \sqrt{2^3} + 1 = 7 \cdot 0.3 + \sqrt{8} + 1 = 2.1 + 2\sqrt{2} + 1 = 3.1 + 2\sqrt{2}\)

3.

\(5\sqrt{0.64} - \sqrt{5^2} + 12^2 = 5 \cdot 0.8 - 5 + 144 = 4 - 5 + 144 = 143\)

4.

\(\sqrt{5 \frac{4}{9}} - \sqrt{1 \frac{11}{25}} + 0.07\sqrt{10000} = \sqrt{\frac{49}{9}} - \sqrt{\frac{36}{25}} + 0.07 \cdot 100 = \frac{7}{3} - \frac{6}{5} + 7 = \frac{35 - 18}{15} + 7 = \frac{17}{15} + 7 = 1\frac{2}{15} + 7 = 8\frac{2}{15}\)