Question

помогите, пожалуйста

Answer 1

$\frac{ \sqrt{3} -3}{3 \sqrt{2}- \sqrt{6} } = \frac{ \sqrt{3} -\sqrt{3}\sqrt{3}}{\sqrt{3}\sqrt{3} \sqrt{2}- \sqrt{2}\sqrt{3} } =\frac{ -\sqrt{3} (\sqrt{3}-1)}{\sqrt{3}\sqrt{2}( \sqrt{3}- 1) }=\frac{ -1}{\sqrt{2}}=- \frac{ \sqrt{2} }{2}$

$\frac{9a-b^2}{9a-6b \sqrt{a} +b^2} = \frac{(3 \sqrt{a}-b )(3 \sqrt{a} +b)}{(3 \sqrt{a} -b)^2} = \frac{3 \sqrt{a} +b}{3 \sqrt{a} -b}$