Question

Rationalise the denominators of the following.
1)1/√7
2)1/√7-2

Answer 1

Answer:

$\frac{1}{ \sqrt{7} } = \frac{1}{ \sqrt{7} } \times \frac{ \sqrt{7} }{ \sqrt{7} } = \frac{ \sqrt{7} }{7} \\ \frac{1}{ \sqrt{7} - 2} = \frac{1}{ \sqrt{7} - 2 } \times \frac{ \sqrt{7} + 2}{ \sqrt{7} + 2 } \\ \: \: = \frac{ \sqrt{7} + 2 }{5}$