Hey there !
Yeah , the problem is absolutely correct , and here is the solution -
[tex]y = {2}^{3x - 1} [/tex]
To find inverse , first switch x and y ,
[tex]x = {2}^{3y - 1} [/tex]
Taking log both sides ,
[tex] log(x) = (3y - 1) log(2) \\ \\ \frac{ log(x) }{ log(2) } = 3y - 1 \\ \\ \: \: y = \frac{ log_{2}(x) }{3} \: \: \: \: \: \: ans.[/tex]
Hope it helps you :)