amsmath：请求改进格式以显示指数乘以小数指数

Question

分数指数到一位数指数（基本上是一个幂到另一个幂）分布的 mwe 渲染如下所示：

在我看来，指数中的乘法似乎有点难以阅读。有没有更好的格式化解决方案？

另外，我的代码中什么导致了枚举以粗体？

非常感谢您的帮助！

姆韦

\documentclass[12pt]{exam}
\printanswers
% un-comment to print solutions.
\renewcommand{\solutiontitle}{}
\usepackage{amsmath}
\usepackage{cancel}
\usepackage{framed}
\usepackage{bm}
\usepackage{multicol}
\usepackage[nice]{nicefrac}
\usepackage{tasks}
\usepackage[a4paper,margin=0.5in,include head]{geometry}
\usepackage{xcolor}
\usepackage{soul}
\pagestyle{head}
\header{Algebra II: Unit 13 A\&B Fractional Exponents}
       {}
       {Due 05/02/23} 

\newcommand{\pagetop}{%
%\noindent 
\bigskip
  \vspace{0.5mm}
}
\newlength{\lwidth}% added <<<<<
\settowidth{\lwidth}{(99)\enspace} % added

\settasks{after-item-skip=1em,
    after-skip=2cm,
    label-width=\lwidth, % changed <<<<<<<<<
    item-indent=0pt,   % changed <<<<<<<<<<
    label-format = \bfseries, % numbers in bold added <<<<<<<<<<
    label=(\arabic*), % 
    label-offset = -\lwidth,% added <<<<<
    item-format = \hspace{\lwidth},% added <<<<<
    column-sep=2em,    % changed <<<<<<<<<  
}

\begin{document}
%definition for bigskip = 1 line to replace all \bigskip
\def\bigskip{\vskip\bigskipamount}
\begin{tasks}
[style=enumerate](3)
%%
%%%% Prob #16
\task
$(a^3b^5)^{1/6}$
\begin{solutionorbox}[5cm]
$(a^{3\bm{\cdot}1/6})(b^{5\bm{\cdot}1/6})$
\bigskip
$(a^{1/2})(b^{5/6})$
\bigskip
\colorbox{yellow}{$\sqrt{a}\sqrt[6]{b^5}$}
\end{solutionorbox}
\vspace{0.25cm}
%%
\end{tasks}
\end{document}