a)
\frac{4^3*4^{-2}+5^{-4}*5^3}{9^{-6}:9^{-7}+(0,47)^0}=\frac{4+5^{-1}}{9^{-6-(-7)}+1}=
=\frac{4+\frac{1}{5}}{9^1+1}=\frac{4+0,2}{10}=4,2:10=0,42
lub
0,42=\frac{42}{100}=\frac{21}{50}
b)
\frac{27^5:81^4-(2^{-1})^{-3}}{(-9)^{-2}}=\frac{(3^3)^5:(3^4)^4-2^3}{(-\frac{1}{9})^2}=
=\frac{3^{15}:3^{16}-8}{\frac{1}{81}}=\frac{3^{-1}-8}{\frac{1}{81}}=\frac{-7\frac{2}{3}}{\frac{1}{81}}=-\frac{23}{3}*\frac{81}{1}=-\frac{23*27}{1*1}=-621