Question

Помогите со всеми вопросами кроме 4, даю все 40 балов за правильный ответ.

Answer 1

$\displaystyle\bf\\1)\\\\\sqrt{81} =\sqrt{9^{2} }=9\\\\2)\\\\\sqrt{0,36} =\sqrt{0,6^{2} } =0,6\\\\3)\\\\\sqrt{\frac{25}{169} } =\sqrt{\Big(\frac{5}{13} \Big)^{2} } =\frac{5}{13} \\\\5)\\\\\sqrt{16+9} =\sqrt{25} =\sqrt{5^{2} } =5\\\\6)\\\\\sqrt{36} -\sqrt{49} =\sqrt{6^{2} } -\sqrt{7^{2} } =6-7=-1\\\\7)\\\\\sqrt{9^{2} -4\cdot 8} =\sqrt{81-32} =\sqrt{49} =\sqrt{7^{2} } =7\\\\8)\\\\\sqrt{9^{2} -4\cdot 8} =\sqrt{81-32} =\sqrt{49} =\sqrt{7^{2} } =7\\\\9)$

$\displaystyle\bf\\2\sqrt{225} -3\sqrt{121} =2\sqrt{15^{2} } -3\sqrt{11^{2} }=2\cdot 15-3\cdot 11=30-33=-3 \\\\10)\\\\3\sqrt{16} +\sqrt{81} =3\sqrt{4^{2} }+\sqrt{9^{2} }=3\cdot 4+9=12+9=21$