Иррациональные уравнения

1. 1) $\frac{(\sqrt{6}+\sqrt{14})^{2}}{10+\sqrt{84}}=\frac{6+2\sqrt{84}+14}{10+2\sqrt{21}}=\frac{6+2*2\sqrt{21}+14}{10+2\sqrt{21}}=\frac{6+4\sqrt{21}+14}{10+2\sqrt{21}}=\frac{20+4\sqrt{21}}{10+2\sqrt{21}}=\frac{(20+4\sqrt{21})(10-2\sqrt{21})}{16}=\frac{4(5+\sqrt{21})*2(5-\sqrt{21})}{16}=\frac{(5+\sqrt{21})*2(5-\sqrt{21})}{4}=\frac{(5+\sqrt{21})(5-\sqrt{21})}{2}=\frac{25-21}{2}=\frac{4}{2}=2$
2) $\frac{\sqrt[3]{3}\sqrt[3]{18}}{\sqrt[3]{2}} = \frac{\sqrt[3]{54}}{\sqrt[3]{2}}= \frac{3\sqrt[3]{2}}{\sqrt[3]{2}}=3$
3) $\sqrt[4]{64}\sqrt[12]{64}=\sqrt[12]{64^{3}}\sqrt[12]{64}=\sqrt[12]{64^{3}*64}= \sqrt[12]{64^{4}}=\sqrt[3]{64}=4$