# Left aligning centered equations

I have set of equations which I would like to just assign one number to. The equations should be aligned at the center of the page. The problem is that I would like all equations to begin at the same point whereas now they end at the same point. I use the \usepackage{amsmath}. Using the following input:

\begin{equation}
\begin{aligned}
u_1 = \partial \phi_1 / \partial x + \partial \psi_1 / \partial z \\
w_1 = \partial \phi_1 / \partial z - \partial \psi_1 / \partial x \\
u_2 = \partial \phi_2 / \partial x \\
w_2 = \partial \phi_2 / \partial z
\label{eq2.23}
\end{aligned}
\end{equation}


I get the following output: The problem is that I want the u2 and w2 to appear directly below u1 and w1. If anyone can help me with this, I would greatly appreciate it!

• Or put & at the beginning of each row to align the left-hand edge. – Andrew Swann Dec 4 '15 at 9:31

Use the alignment tab & to justify the equations, i.e. substitute = by &=.

\documentclass{article}
\usepackage{mathtools}
\begin{document}
\begin{equation}
\begin{aligned}
u_1 &= \partial \phi_1 / \partial x + \partial \psi_1 / \partial z \\
w_1 &= \partial \phi_1 / \partial z - \partial \psi_1 / \partial x \\
u_2 &= \partial \phi_2 / \partial x \\
w_2 &= \partial \phi_2 / \partial z
\label{eq2.23}
\end{aligned}
\end{equation}
\end{document} • Thanks a lot. I didn't realize it was that easy :). Really appreciate it! – Kristian Dec 4 '15 at 9:33
• @Kristian If you want to learn more about the possibilities in mathmode, this might be interesting. – Henri Menke Dec 4 '15 at 9:34