Powers, roots, exponentiation and logarithms

Answer all the questions below and press submit to see how many you got right.

id: 10807

What is $m$ in $5^{x}\cdot 5^{x}=m^x?$

id: 10694

What is $m$ in $x^{-1}\cdot x^{-1}=x^m?$

id: 10289

$(\sqrt{42}+\sqrt{81})\cdot(\sqrt{42}-\sqrt{81})=?$