[Tex/LaTex] left align using alignat

alignalignat

I want to align some equations on the left side in a document. And additionally I want to have some aligned text behind every equation. Also the equations need to be numbered. With the code below my goal is almost achieved. I just need to bring the text aligned to the right… How do I do that? Thanks

\documentclass[a4paper, 11pt]{book}
\usepackage{amsmath}
\begin{document}
\begin{flalign}
    &u_\mathrm{L} = L \cdot \frac{\text{d}i_\mathrm{L}}{\text{d}t} \quad(\text{Differentialform}) &\label{eq:2_19} \\
    &i_\mathrm{L} = \frac{1}{L} \cdot \int\limits_t u_\mathrm{L} \text{d}t + i_\mathrm{L}(t=0) \quad (\text{Integralform}) &\label{eq:2_20}
\end{flalign}
\end{document}

Best Answer

... or just rearrange ampersands:

\documentclass[a4paper, 11pt]{book}
    \usepackage{amsmath}
\begin{document}
    \begin{flalign}
u_\mathrm{L}    &   = L \cdot \frac{\text{d}i_\mathrm{L}}{\text{d}t}       
    &       
                &   \text{(Differentialform)}       &       &   \\
i_\mathrm{L}    & = \frac{1}{L} \cdot \int\limits_t u_\mathrm{L} \text{d}t + i_\mathrm{L}(t=0)     
    &       
                &   \text{(Integralform)}           &       &   
    \end{flalign}
\end{document}
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