allign image center bottom latex code example

Example 1: center image latex

\begin{center}
    \includegraphics{yourimage}
\end{center}

Example 2: latex eqnarray centering

\begin{eqnarray*}
    &x + (y - 2)^4 = w^2 \\
    &(x  - 9)^2 + y_2^2 = w^2 \\
    &x + (y - 2)^4 = w^2 = (x  - 9)^2 + y_2^2 \\
\end{eqnarray*}