[Tex/LaTex] Putting text next to an equation without moving the equation to the side

Question

I want to write something like:

\begin{equation}
f(x)=y \quad \text{(This is the equation lala)}
\end{equation}

But this essentially moves the equation out of the center.
I don't want the equation not being centered anymore. I rather want the text on the right of the centered equation. Is there an easy solution (like naming an equation and letting that appear somehow…)?

Answer 1

So you want to align something?

\begin{align}
f(x)&=y &&\text{tralala}
\end{align}

if you want to stick with equation you could simply tell latex to ignore the width of the text

\begin{equation}
f(x)=y \rlap{\quad \text{tralala}}
\end{equation}