Answer :
When you have (a^b)*(a^c), you can factor it by a^(b+c), in this case, it goes as follows:
[tex](\frac{1}{3})^5\cdot(\frac{1}{3})^8=(\frac{1}{3})^{5+8}=(\frac{1}{3})^{13}=\frac{1}{3^{13}}[/tex]
When you have (a^b)*(a^c), you can factor it by a^(b+c), in this case, it goes as follows:
[tex](\frac{1}{3})^5\cdot(\frac{1}{3})^8=(\frac{1}{3})^{5+8}=(\frac{1}{3})^{13}=\frac{1}{3^{13}}[/tex]