Answer:
[tex]{ \rm{ {( \frac{1}{ \sqrt{3} }) }^{7} }} \\ [/tex]
• First rationalise the denominator:
[tex] = { \rm{ {( \frac{1 \times \sqrt{3} }{ \sqrt{3} \times \sqrt{3} }) }^{7} }} \\ \\ = { \rm{ {( \frac{ \sqrt{3} }{3}) }^{7} }}[/tex]
• Open the bracket, by distributing the power to both the numerator and denominator:
[tex] = { \rm{ \frac{( \sqrt{3} ) {}^{6} \times \sqrt{3} }{ {3}^{7} } }} \\ \\ = { \rm{ \frac{27 \sqrt{3} }{2187} }} \\ \\ = { \rm{ \frac{ \sqrt{3} }{81} }}[/tex]
b is 3 and c is 81