tolong bantu jawab yah , beserta caranya yang lengkap dan panjang

1.
a)
[tex] = \frac{1}{ \sqrt{5} } \times \frac{ \sqrt{5} }{ \sqrt{5} } \\ = \frac{ \sqrt{5} }{5} \\ = \frac{1}{5} \sqrt{5} [/tex]
b)
[tex] = \frac{2}{ \sqrt{7} } \times \frac{ \sqrt{7} }{ \sqrt{7} } \\ = \frac{2 \sqrt{7} }{7} \\ = \frac{2}{7} \sqrt{7} [/tex]
c)
[tex] = \frac{ - 7}{ \sqrt{11} } \times \frac{ \sqrt{11} }{ \sqrt{11} } \\ = \frac{ - 7}{11} \sqrt{11} [/tex]
Nomor 2
a)
[tex] = \frac{1}{ \sqrt{5} + 1} \times \frac{ \sqrt{5} - 1}{ \sqrt{5} - 1 } \\ = \frac{ \sqrt{5} - 1}{5 - 1} \\ = \frac{1}{4} \sqrt{5} - \frac{1}{4} \\ = \frac{1}{4} ( \sqrt{5} - 1)[/tex]