Suppress coefficient 1 in polynomial

Question

Is there a way to suppress the coefficient 1 in front of a in the following calculation?

\documentclass{article}
\usepackage{polynom}
\begin{document}
    [
        \polylongdiv{x^3 + ax^2 - x + 4}{x - 1}
    ]
\end{document}

Answer 1

There is an old question and I think that your question it is a duplicate of this question: Expand LaTeX macros to modify. I have used the excellent macro of the answer of Sep 18 '13 at 20:45 of the user @Heiko Oberdiek, for example, that delete the coefficient 1. Or if you prefer work correctly also the macro of @David Carlisle. Here there is an example.

\documentclass[a4paper,12pt]{article}
\usepackage{polynom}
\makeatletter
\let\pldx@saved@PrintRational\pld@PrintRational
\renewcommand{\pld@PrintRational}[2]{%
  \def\pldx@do{\pldx@PrintRational{#1}{#2}}%
  \futurelet\pldx@token\pldx@do
}
\newcommand{\pldx@PrintRational}[2]{%
  \let\pldx@do@firstofone
  \ifx\pldx@token\pld@S
    \def\pldx@a{#1}%
    \def\pldx@b{#2}%
    \ifx\pldx@a\pldx@b
      \let\pldx@do@gobble
    \fi
  \fi
  \pldx@do{%
    \pldx@saved@PrintRational{#1}{#2}%
  }%
}
\makeatother
\begin{document}
[\polylongdiv{x^3 + ax^2 - x + 4}{x - 1}]
\end{document}