Question

помогите пожалуйста 9 класс​

Answer 1

$\displaystyle\bf\\1)\\\\0,5\sqrt{256}=0,5\sqrt{16^{2} } =0,5\cdot 16= 8\\\\2)\\\\-5\sqrt{0,64} =-5\sqrt{0,8^{2} } =-5\cdot 0,8=-4\\\\3)\\\\0,3\sqrt{\frac{25}{9} } =0,3\sqrt{\Big(\frac{5}{3}\Big)^{2} }=0,3\cdot\frac{5}{3} =0,1\cdot 5=0,5\\\\4)\\\\\frac{\sqrt{0,16} }{2\sqrt{0,04} } =\frac{1}{2} \cdot\sqrt{\frac{0,16}{0,04} }=\frac{1}{2}\cdot\sqrt{4} =\frac{1}{2} \cdot 2=1\\\\5)\\\\\sqrt{4900}-\sqrt{289} =\sqrt{70^{2} } -\sqrt{17^{2} } =70-17=53$

$\displaystyle\bf\\6)\\\\0,07\sqrt{10000} -\sqrt{36} =0,07\sqrt{100^{2} } -\sqrt{6^{2} } =0,07\cdot 100-6=\\\\=7-6=1\\\\7)\\\\\frac{\sqrt{81} }{\sqrt{361} } +\sqrt{\frac{1}{4} } =\frac{\sqrt{9^{2} } }{\sqrt{19^{2} } } +\sqrt{\Big(\frac{1}{2}\Big)^{2} } =\frac{9}{19} +\frac{1}{2}=\frac{9\cdot 2+1\cdot 19}{19\cdot 2} =\\\\\\=\frac{18+19}{38} =\frac{37}{38} \\\\8)$

$\displaystyle\bf\\\sqrt{1\frac{9}{16} } +\sqrt{\frac{121}{25} } =\sqrt{\frac{16+9}{16} } +\sqrt{\Big(\frac{11}{5}\Big)^{2} } =\sqrt{\frac{25}{16} }+\frac{11}{5} =\\\\\\=\frac{5}{4}+2,2=1,25+2,2= 3,45\\\\9)\\\\\sqrt{2\frac{7}{81} }-\frac{1}{\sqrt{36} } = \sqrt{\frac{162+7}{81} }-\frac{1}{\sqrt{6^{2} } } =\sqrt{\frac{169}{81} } -\frac{1}{6} =\\\\\\=\frac{13}{9} -\frac{1}{6}=\frac{13\cdot 2-1\cdot 3}{18}=\frac{26-3}{18} =\frac{23}{18}=1\frac{5}{18}$