Math & Science ⇒ align multiple multi-lined equations

[pkladisios]

I have four consecutive equations and wish their equal signs and their numbering to be aligned. So far, i have only achieved the second by individually using equation and split environments. Here's the minimal code:

Code: Select all

\documentclass[twocolumn]{article}

\usepackage{amsmath} %math 

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%RT20
\begin{center}
\underline{\textbf{RT20}}
\end{center}

\begin{equation}
\begin{split}
C_{peff}&=444.4711352-170.5210626T\\
&+25.80658991T^{2}-1.912462169T^{3}\\
&+0.06910480624T^{4}-0.0009667426392T^{5}\\
&\text{for } 15^{o}C<T<19.5^{o}C
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C_{peff}&=5529.086311-565.4394794T\\
&+14.50378915T^{2}\\
&\text{for } 19.5^{o}C<T<20.5^{o}C
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C_{peff}&=3780.001949-342.8478233T\\
&+7.797040983T^{2}\\
&\text{for } 20.5^{o}C<T<22^{o}C
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C_{peff}&=3735.906512-536.9879458T\\
&+28.98735267T^{2}-0.6959772441T^{3}\\
&+0.006270432248T^{4}\\
&\text{for } 22^{o}C<T<26^{o}C
\end{split}
\end{equation}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\end{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[Johannes_B]

Every equation is independant from the others. What you are looking for is the align environment.

Code: Select all

\documentclass[twocolumn]{article}

\usepackage{mathtools} %JB: Some improvements over amsmath
\usepackage{siunitx}

\begin{document}

\begin{center}
	\underline{\textbf{RT20}}
\end{center}

\begin{align}
	\begin{split}
		C_{p\mathrm{eff}}&=444.4711352-170.5210626T\\
		&+25.80658991T^{2}-1.912462169T^{3}\\
		&+0.06910480624T^{4}-0.0009667426392T^{5}\\
		&\text{for } \SI{15}{\celsius}<T<\SI{19.5}{\celsius}
	\end{split}\\
	\begin{split}
		C_{p\mathrm{eff}}&=5529.086311-565.4394794T\\
		&+14.50378915T^{2}\\
		&\text{for } \SI{19.5}{\celsius}<T<\SI{20.5}{\celsius}
	\end{split}\\
	\begin{split}
		C_{p\mathrm{eff}}&=3780.001949-342.8478233T\\
		&+7.797040983T^{2}\\
		&\text{for } \SI{20.5}{\celsius}<T<\SI{22}{\celsius}
	\end{split}\\
	\begin{split}
		C_{p\mathrm{eff}}&=3735.906512-536.9879458T\\
		&+28.98735267T^{2}-0.6959772441T^{3}\\
		&+0.006270432248T^{4}\\
		&\text{for } \SI{22}{\celsius}<T<\SI{26}{\celsius}
	\end{split}
\end{align}

\end{document}