\documentclass[a4paper,10pt]{article}
\usepackage{myXsim}
\usepackage{pgfplots}
\pgfplotsset{compat = newest}
\usepgfplotslibrary{external} 
\tikzexternalize


\author{Benjamin Bertrand}
\title{Fonctions et graphiques - Cours}
\date{Septembre 2021}

\DeclareExerciseCollection[step=4bis]{banque}
\xsimsetup{collect}

\thispagestyle{empty}


\begin{document}

\input{exercises.tex}

\setcounter{exercise}{6}

\printcollection{banque}
\vfill

\begin{multicols}{2}
\printsolutionstype{exercise}
\end{multicols}

\end{document}