Thickness of the fraction line

Question

I want to make this fraction line thicker:

\documentclass{beamer}
\usepackage{tgheros}
\renewcommand\familydefault{\sfdefault}
\usepackage{mathastext}
%
\makeatletter
\mathchardef\standardplus=\mathcode`+
\DeclareRobustCommand{\tauyecoplus}{%
  \mathbin{\mathpalette\tauyeco@plus\relax}%
}
\newcommand{\tauyeco@plus}[2]{
  \raisebox{-0.1\height}{\scalebox{1.4}{$\m@th#1\standardplus$}}%
}
\begingroup\lccode`~=`+ \lowercase{\endgroup\let~}\tauyecoplus
\AtBeginDocument{\mathcode`+="8000 }
\makeatother
%
\DeclareRobustCommand{\bfrac}[2]{%
  \mathchoice{\frac{\raisebox{0.1ex}{$#1$}}{\raisebox{-0.1ex}{$#2$}}}%
         {\frac{\raisebox{0.4ex}{$\scriptstyle#1$}}{\raisebox{0.1ex}{$\scriptstyle#2$}}}%
             {\frac{#1}{#2}}%
             {\frac{#1}{#2}}%
}
%
\begin{document}
\begin{frame}
\[\frac{(x+y)^2}{B_x}\]
\end{frame}
\end{document}