Помогите ,пожалуйста решить пример

1) $\frac{3}{7}^3 - \frac{16}{21} = \frac{9-16}{21}= -\frac{7}{21} =- \frac{1}{3}$
2) $\frac{11}{15}+0,3= \frac{11}{15}^2 + \frac{3}{10} ^3= \frac{22+9}{30}= \frac{31}{30} = 1\frac{1}{30}$
3) $- \frac{1}{3}* 2 \frac{1}{7} = - \frac{1}{3}* \frac{15}{7} = -\frac{1*15}{3*7} =- \frac{5}{7}$
4) $1\frac{1}{30}: 12\frac{2}{5} = \frac{31}{30} : \frac{62}{5} = \frac{31*5}{30*62} = \frac{1}{12}$
5) $-\frac{5}{7}^{12} +\frac{1}{12}^7= \frac{-60+7}{84} = -\frac{53}{84}$