Помогите решить (9^-2* 3^-5)/ (81*27^-3)

=27³/(81·9²·3^5)=(3³)³/(3^4·(3²)²·3^5)=

=3^9/(3^4·3^4·3^5)=3^9/3^(4+4+5)=3^9/3^13=3^(9-13)=3^(-4)=1/3^4=1/81