Question

alguem me ajuda pfv pfv​

Answer 1

$\ \ \ (8-0,7^2)\cdot\sqrt{\frac{49}{25}}\\= \Big[8- \big(\frac{7}{10}\big)^2 \Big] \cdot \frac{7}{5}\\= \Big[8- \frac{49}{100}\Big] \cdot \frac{7}{5}\\= \Big[\frac{800}{100}- \frac{49}{100}\Big] \cdot \frac{7}{5}\\\\= \Big[\frac{800-49}{100}\Big] \cdot \frac{7}{5}\\\\= \frac{751}{100} \cdot \frac{7}{5}\\\\= \frac{5257}{500}$

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$\frac{2}{3} :\frac{8}{9} \cdot\sqrt{0,25} =\frac{2}{3} :\frac{8}{9} \cdot\sqrt{\frac{25}{100}} =\frac{2}{3} :\frac{8}{9} \cdot\frac{5}{10}} =\frac{2}{3} \cdot\frac{9}{8} \cdot\frac{5}{10}} =\frac{90^{:30}}{240_{:30}} =\frac{3}{8}$

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$\ \ \ \sqrt{\frac{9}{16}}\cdot \frac{4}{5}+(0,2)^2 \\\\ = \frac{3}{4}\cdot \frac{4}{5}+\big( \frac{2}{10} \big)^2\\\\ = \frac{12}{20}+ \frac{4}{100} \\\\ = \frac{60}{100}+ \frac{4}{100} \\\\ = \frac{60+4}{100}\\\\ = \frac{64^{:4}}{100_{:4}}\\\\=\frac{16}{25}$

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$\ \ \ 5,1-\big( \frac{3}{5} \big)^3 :(2-\sqrt{1,44})\\\\=\frac{51}{10} -\frac{27}{125} :\Big(2-\sqrt{\frac{144}{100}}\Big)\\\\=\frac{51}{10} -\frac{27}{125} :\Big(2-\frac{12}{10}\Big)\\\\=\frac{51}{10} -\frac{27}{125} :\Big(\frac{20}{10}-\frac{12}{10}\Big)\\\\=\frac{51}{10} -\frac{27}{125} :\Big(\frac{20-12}{10}\Big)\\\\=\frac{51}{10} -\frac{27}{125} :\frac{8}{10}\\\\=\frac{51}{10} -\frac{27}{125} \cdot\frac{10}{8}\\\\=\frac{51}{10} -\frac{270}{1000}\\\\=\frac{5100}{1000} -\frac{270}{1000}$

$\\=\frac{5100-270}{1000}\\\\=\frac{4830}{1000}\\\\=\frac{483}{100}$