Latex formulas written Wrap

latex when writing a formula often encounter long formulas or equal to the continuous, then you can choose a line feed formula:

\begin{equation}
    \begin{aligned}
        a &= b+c\\
          &= c+b
    \end{aligned}
\end{equation}

The following effects:

Wherein the label is a need & alignment position, such as the example code in "=" front, two lines of the equal sign is intended to align the formula; and \\ are placed in the desired position change start line.