I was doing this problem and I simplified everything to this:
$$243 = 3^{\frac{m}{10}}$$
However, after that part I got stuck. Because I tried doing this then:
$$\sqrt[10]{243} = 3^m$$
But then I couldn't do anything else so I got stuck.
However on the explanation they give us the hint of using:
$$3 = 243^{\frac{1}{5}}$$
And then I know I could be able to replace the 3 in the original equation and go from there. However I do not understand how 3 is equal to 243 to the power of 1/5, how do you get to that conclusion?