tolong bantuin pliss terimaksih

1.
[tex] = \frac{5}{ \sqrt{11} } \times \frac{ \sqrt{11} }{ \sqrt{11} } \\ = \frac{5}{11} \sqrt{11} [/tex]
2.
[tex] = \frac{ \sqrt{3} }{ \sqrt{ \frac{5}{7} } } \times \frac{ \sqrt{ \frac{5}{7} } }{ \sqrt{ \frac{5}{7} } } \\ = \frac{ \sqrt{ \frac{15}{7} } }{ \frac{5}{7} } \\ = \frac{7}{5} \sqrt{ \frac{15}{7} } [/tex]
3.
[tex] = \frac{2}{ \sqrt{3} + 5 } \times \frac{ \sqrt{3} - 5}{ \sqrt{3} - 5 } \\ = \frac{2 \sqrt{3} - 10 }{3 - 25} \\ = - \frac{1}{11} \sqrt{3} + \frac{5}{11} [/tex]