# Several “equations” in the same line [closed]

\begin {eqnarray}
P(N(t)=n)=P(T_{n}\leq t)- P(T_{n+1}\leq t)=e^{-\lambda*t}*\frac {(\lamda*t)^{n}}{n!}
\end {eqnarray}


I want to write this in latex however and it gives me an error, can I help me?

## closed as off-topic by egreg, Stefan Pinnow, Circumscribe, marmot, dexteritasJan 12 at 12:19

• This question does not fall within the scope of TeX, LaTeX or related typesetting systems as defined in the help center.
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• Welcome to TeX SX! Please post a minimal compîlable code. – Bernard Jan 12 at 10:01
• I'm voting to close this question as off-topic because the error is due to a typo, lamda instead of lambda – egreg Jan 12 at 10:37
• Don't use eqnarray; in this case use equation. Fix the typo and you'll be OK. In future questions, please add information about the errors you get. – egreg Jan 12 at 10:38
• As for why eqnarray is bad, see the links in this answer. – Circumscribe Jan 12 at 11:58

Error cleared (\lamda replaced with \lambda):

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin {equation}
P(N(t)=n)=P(T_{n}\leq t)- P(T_{n+1}\leq t)=e^{-\lambda*t}*\frac {(\lambda*t)^{n}}{n!}
\end {equation}

\end{document}


• eqnarray is not to be used. In this case equation is the best choice. – egreg Jan 12 at 10:36