我如何使这个等式左对齐？

Question

我在 LaTeX 中写了一个方程式，它是居中的。我怎样才能将其左对齐，但不丢失分割？（我仍然希望等号一个接一个）。

代码：

\begin{equation*}
\begin{split}
a &=(3+6+9+12+...+147)+1125\\
&=3 \cdot (1+2+3+4+...+49)+1125\\
&=3 \cdot \displaystyle\frac{49 \cdot 50}{2} + 1125=49 \cdot 75 + 1125\\
&=3675 + 1125\\
&=4900\\
&=70^2 \Rightarrow \sqrt{a} = \sqrt{70^2}=70 \end{split}
\end{equation*}

Answer 1

我觉得没有理由将此显示屏放在左侧。无论如何……

\documentclass{article}
\usepackage{amsmath}

\begin{document}

The following display is left aligned. I don't know why it should be
treated differently from the other displays, but here it is anyhow.
\begin{flushleft}
$\begin{aligned}
a &=(3+6+9+12+\dots+147)+1125\\
  &=3 \cdot (1+2+3+4+\dots+49)+1125\\
  &=3 \cdot \frac{49 \cdot 50}{2} + 1125=49 \cdot 75 + 1125\\
  &=3675 + 1125\\
  &=4900\\
  &=70^2 \Rightarrow \sqrt{a} = \sqrt{70^2}=70
\end{aligned}$
\end{flushleft}
Note that dots should be specified with \verb|\dots|, not with
three periods and that \verb|\displaystyle| is not needed; there
is \verb|\dfrac|, if needed (not here).

\end{document}

Answer 2

我不确定这是否正是您想要的，但您可以将\parbox宽度设置为 0 来实现这一点。

\noindent Previous line.

\noindent\parbox{0mm}{
\begin{equation*}
\begin{split}
a &=(3+6+9+12+...+147)+1125\\
&=3 \cdot (1+2+3+4+...+49)+1125\\
&=3 \cdot \displaystyle\frac{49 \cdot 50}{2} + 1125=49 \cdot 75 + 
1125\\
&=3675 + 1125\\
&=4900\\
&=70^2 \Rightarrow \sqrt{a} = \sqrt{70^2}=70 \end{split}
\end{equation*}
}

\noindent Next line.