Вычислите:
а) $(1\frac{1}{3})^{18} : (1\frac{1}{3})^{17}$;
б) $(-2\frac{1}{7})^{6} : (-2\frac{1}{7})^{4}$;
в) $(3\frac{2}{9})^{23} : (3\frac{2}{9})^{21}$;
г) $(-1\frac{7}{8})^{15} : (-1\frac{7}{8})^{14}$.
$(1\frac{1}{3})^{18} : (1\frac{1}{3})^{17} = (1\frac{1}{3})^{18 - 17} = (1\frac{1}{3})^{1} = 1\frac{1}{3}$
$(-2\frac{1}{7})^{6} : (-2\frac{1}{7})^{4} = (-2\frac{1}{7})^{6 - 4} = (-2\frac{1}{7})^{2} = (-\frac{15}{7})^{2} = \frac{225}{49} = 4\frac{29}{49}$
$(3\frac{2}{9})^{23} : (3\frac{2}{9})^{21} = (3\frac{2}{9})^{23 - 21} = (3\frac{2}{9})^{2} = (\frac{29}{9})^{2} = \frac{841}{81} = 10\frac{31}{81}$
$(-1\frac{7}{8})^{15} : (-1\frac{7}{8})^{14} = (-1\frac{7}{8})^{15 - 14} = (-1\frac{7}{8})^{1} = -1\frac{7}{8}$