a) \(\frac{205.5^{10}}{100^5}=\frac{41.5^{11}}{5^2.4}=\frac{41.5^9}{4}\)
b) \(\frac{\left(0,9\right)^5}{\left(0,3\right)^5}=\left(0,9:0,3\right)^5=3^5=243\)
c) \(\frac{6^2+3.6+3^2}{-13}=\frac{2^2.3^2+3.6+3^2}{-13}=\frac{3\left(2^2.3+6+3\right)}{-13}=\frac{3.21}{-13}=\frac{63}{-13}\)
d) \(\frac{4^6.9^5.6^9.120}{8^4.3^{12}-6^{11}}=\frac{\left(2^2\right)^6.\left(3^2\right)^5.\left(2.3\right)^9.2^3.3.5}{\left(2^3\right)^4.3^{12}-\left(2.3\right)^{11}}=\frac{2^{24}.3^{20}.5}{2^{12}.3^{12}-2^{11}.3^{11}}=\frac{2^{24}.3^{20}.5}{2^{11}.3^{11}.\left(2.3-1\right)}=\frac{2^{13}.3^9.5}{5}=2^{13}.3^9\)