Answer :
[tex]\frac{9}{10}^{(3}-\frac{1}{15}^{(2}= \frac{27-2}{30}= \boxed{\frac{25}{30}=\frac{5}{6}}[/tex]
[tex] \frac{9}{10}- \frac{1}{15}= \frac{9*3}{10*3}- \frac{2}{15*2} = \frac{27}{30}- \frac{2}{30} = \frac{25}{30}= \frac{5}{6} [/tex]