Question

будь ласка на завтра нада даю 100 балів​

Answer 1

I група

1) $\sqrt{64} + \sqrt{25} = 8 + 5 = 13$

2) $2\sqrt{100} - \sqrt{144} = 2*10 - 12 = 8$

3) $5\sqrt{0,36} + 4\sqrt{0,64} = 5*0,6 + 4*0,8 = 3 + 3,2 = 6,4$

4) $\sqrt{64} : \sqrt{0,25} = 8 : 0,5 = 16$

II група

1)

$2x^2=50\\x^2 = 25\\x_{1} = 5\\x_{2} = -5$

2)

$(x-5)*(x+5) = 24\\x^2-25 = 24\\x^2 = 49\\x_{1} = 7\\x_{2} = -7$

3)

$\sqrt{x-1} = 3\\x-1 = 9\\x = 10$

4)

$2\sqrt{2x+7} - 6 = 0\\\\2\sqrt{2x+7} = 6\\\\\sqrt{2x+7} = 3\\\\2x+7 = 9\\2x = 2\\x = 1$

III група

1) $\sqrt{1,44*0,16*400} = 1,2 * 0,4 * 20 = 9,6$

2) $\sqrt{0,4}*\sqrt{0,9} = \sqrt{0,4*0,9} = \sqrt{0,36} = 0,6$

3) $\sqrt{70,56} - (\frac{1}{2} \sqrt{42})^2 = 8,4 - \frac{1}{4} *42 = 8,4-10,5 = -2,1$

4) $\sqrt{4\frac{21}{25}*23\frac{73}{81}} = \sqrt{\frac{121}{25}*\frac{1936}{81}} = \frac{11}{5} * \frac{44}{9} = \frac{484}{45}$

IV група

1) $(\sqrt{63} - \sqrt{28}) * \sqrt{7} = (3\sqrt{7}-2\sqrt{7})*\sqrt{7}= \sqrt{7}*\sqrt{7}= 7$

2) $(5-\sqrt{3}) *(3+2\sqrt{3}) = 15 + 10\sqrt{3} - 3\sqrt{3} - 6 = 9 + 7\sqrt{3}$

3) $(3\sqrt{2}+2)*(3\sqrt{2}-2)= 18 - 6\sqrt{2} + 6\sqrt{2} - 4 = 14$

4) $\frac{a-25}{a-5\sqrt{a} } = \frac{(\sqrt{a}-5)*(\sqrt{a}-5)}{\sqrt{a} (\sqrt{a}-5)} = \frac{\sqrt{a} + 5}{\sqrt{a}} = \frac{\sqrt{a}+5}{\sqrt{a}} *\frac{\sqrt{a}}{\sqrt{a}} = \frac{(\sqrt{a}+5)\sqrt{a}}{\sqrt{a}\sqrt{a}} = \frac{a+5\sqrt{a}}{a}$