Помогите пожалуйста)

$1. \\ b_{3} =4, b_{6} = \frac{1}{2} \\ q= \frac{1}{2} \\ b_1=16 \\ S= \frac{b_1}{1-q} = \frac{16}{1- \frac{1}{2} } =32$
$2. \\ a) \sqrt{32} - \sqrt{50} - \sqrt{18} =4 \sqrt{2} -5 \sqrt{2} -3 \sqrt{2} =-4 \sqrt{2} \\ b) \sqrt[3]{3 \sqrt[3]{2} } = \sqrt[3]{ \sqrt[3]{54} } = \sqrt[9]{54}$
$3. \sqrt{1- x^{2} } * \sqrt{x} \\ \left \{ {{x \geq 0} \atop {1-x^{2} \geq 0}} \right. \\ \left \{ {{x \geq 0} \atop { x^{2} \leq 1}} \right. \\ \left \{ {{x \geq 0} \atop {-1 \leq x \leq 1} \right. \\$
x ∈ (0; 1)
$4. \\ a) \frac{ \sqrt{x} - \sqrt{y} }{x-y} = \frac{ \sqrt{x} - \sqrt{y} }{( \sqrt{x} - \sqrt{y} )( \sqrt{x} + \sqrt{y} )} = \frac{1}{ \sqrt{x} + \sqrt{y} } \\ b) \frac{ \sqrt{x} - \sqrt{y} }{ \sqrt[4]{x}- \sqrt[4]{y}}= \frac{( \sqrt[4]{x}- \sqrt[4]{y}) ( \sqrt[4]{x}+ \sqrt[4]{y} ) }{ \sqrt[4]{x}- \sqrt[4]{y}} = \sqrt[4]{x} + \sqrt[4]{y}$