a)
-5*(-5)^9:(-5)^8=-5*(-5)^{9-8}=-5*(-5)=25
b)
(-3)^7:(-3)^6*(-3)^2=(-3)^{7-6}*9=-3*9=-27
c)
(0,7)^6*(1\frac{3}{7})^6-(1,6)^3:(0,8)^3=(\frac{7}{10}*\frac{10}{7})^6-(\frac{1,6}{0,8})^3=1-2^3=-7
d)
(0,9)^9*(1\frac{1}{9})^9-(1,2)^{10}:(1\frac{1}{5})^{10}=(\frac{9}{10})^9*(\frac{10}{9})^9-(1,2)^{10}:(1,2)^{10}=
(\frac{9}{10}*\frac{10}{9})^9-(1,2)^{10-10}=1^9-(1,2)^0=1-1=0