I have this small example,
\documentclass{beamer}
\mode<presentation>
{
\usetheme{Boadilla}
\usecolortheme{wolverine}
\usefonttheme{structurebold}
\setbeamertemplate{navigation symbols}{}
\setbeamertemplate{caption}[numbered]
\setbeamertemplate{itemize items}[ball]
}
\usepackage{array,amsmath,booktabs}
\usepackage{amsmath}
\usepackage[version=4]{mhchem}
\usepackage{mathtools}
\usepackage{graphicx}
\usepackage{subcaption}
\begin{document}
\begin{frame}
\begin{figure}[H]
\centering
\begin{subfigure}[b]{0.28\linewidth}
\includegraphics[clip, trim=1 1.75 3 1, width=50mm,scale=0.35]{Image1}
\caption{Substrate-Enzyme association}
\end{subfigure}
\begin{subfigure}[b]{0.28\linewidth}
\includegraphics[clip, trim=1 1.75 3 1, width=50mm,scale=0.35]{Image2}
\caption{Complex dissociation}
\end{subfigure} \\
\begin{subfigure}[b]{0.3\linewidth}
\includegraphics[clip, trim=1 1.75 3 1, width=50mm,scale=0.35]{Image3}
\caption{Product formation}
\end{subfigure}
\caption{Prior and posterior after 100, 200 and 300 reactions for reaction in Micahelis-Menten model}
\label{fig:boat2}
\end{figure}
\begin{itemize}
\item as more reactions take place, posterior becomes narrower
\end{itemize}
\end{frame}
\end{document}
And I am trying to get these images to align so that I have 2 images on my top row, then the 3rd image and the following line and centred between the 2 top images.
But everything I try the formatting keeps getting worse and worse.


trimarguments of the\includegraphicscommands, meaning that there are conflicting directiveswidth=50mmandscale=0.35. Try with only one of those. – Feb 12 '18 at 19:28