Aligning equations in LaTex

In order to align your equations based on a character (such as =), wrap the code inside \begin{align} and prefix the character with &

$$
\begin{align}
first\ equation &= 2\\
tiny\ eq &= 3
\end{align}
$$

$$\begin{array}{rl}firstequation& =2\\ tinyeq& =3\end{array}$$

Also, as can be observed, using \\ introduces a new line. Without using \\ will render both the equations in the same line.

The \\ only works when the code block is wrapped inside begin{align} and end{align}

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