LaTeX Forum

\documentclass{scrartcl}
\usepackage{amsmath}
\begin{document}

\begin{equation}
 \begin{aligned}
  h &= \left( \frac{y_{i}}{x_{i}} \right) = \lambda f_{1}\left(\frac{y_{i}}{x_{i}}\right) + \left(1-\lambda \right) f_{2}\left(\frac{y_{i}}{x_{i}} \right) \\
    &= \frac{\lambda}{\sqrt{2\Pi}\sigma_{1}}\exp\left(-\frac{ \left(y_{i}-\vec{x_{i}}*\vec{\beta_{1}}  \right)^{2}}{2\sigma_{1}^{2}} \right)  + \frac{1-\lambda}{\sqrt{2\Pi}\sigma_{2}}\exp\left(-\frac{\left(y_{i}-\vec{x_{i}}*\vec{\beta_{2}} \right)^{2}}{2\sigma_{2}^{2}} \right)
 \end{aligned}
\end{equation}

\end{document}

\documentclass{scrartcl}
\usepackage{amsmath}
\begin{document}

\begin{align}
         h &=\left(  \frac{y_{i}}{x_{i}}  \right) = \lambda f_{1}\left(\frac{y_{i}}{x_{i}}\right) + \left(1-\lambda \right) f_{2}\left(\frac{y_{i}}{x_{i}} \right) \\
           &= \frac{\lambda}{\sqrt{2\Pi}\sigma_{1}}\exp\left(-\frac{ \left(y_{i}-\vec{x_{i}}*\vec{\beta_{1}}  \right)^{2}}{2\sigma_{1}^{2}} \right)  + \frac{1-\lambda}{\sqrt{2\Pi}\sigma_{2}}\exp\left(-\frac{\left(y_{i}-\vec{x_{i}}*\vec{\beta_{2}} \right)^{2}}{2\sigma_{2}^{2}} \right)
\end{align}


\end{document}

\documentclass{scrartcl}
\usepackage{amsmath}
\begin{document}

\begin{equation}
      \begin{aligned}
      	h=\left(  \frac{y_{i}}{x_{i}}  \right) = \lambda f_{1}\left(\frac{y_{i}}{x_{i}}\right) + \left(1-\lambda \right) f_{2}\left(\frac{y_{i}}{x_{i}} \right) \\ = \frac{\lambda}{\sqrt{2\Pi}\sigma_{1}}\exp\left(-\frac{ \left(y_{i}-\vec{x_{i}}*\vec{\beta_{1}}  \right)^{2}}{2\sigma_{1}^{2}} \right)  + \frac{1-\lambda}{\sqrt{2\Pi}\sigma_{2}}\exp\left(-\frac{\left(y_{i}-\vec{x_{i}}*\vec{\beta_{2}} \right)^{2}}{2\sigma_{2}^{2}} \right)
      \end{aligned}
\end{equation}

\end{document}