Let
X

How to Write Equations in LaTeX

Updated June 2026

To write equations in LaTeX, use $...$ for inline math (e.g. $E=mc^2$) and the equation environment for numbered display math: \begin{equation} ... \end{equation}. Load amsmath with \usepackage{amsmath} for fractions (\frac), alignment (align), and advanced symbols. LetX renders math live as you type.

Step by step

  1. 1

    Load amsmath

    Add \usepackage{amsmath} for the best math support.

  2. 2

    Inline math

    Wrap math in $...$ to keep it in the text line, e.g. $a^2 + b^2 = c^2$.

  3. 3

    Display math

    Use \begin{equation} ... \end{equation} for a centered, numbered equation.

  4. 4

    Align multiple lines

    Use the align environment with & alignment points and \\ between lines.

  5. 5

    Compile

    Compile to PDF; LetX shows rendered math in the live preview in seconds.

Example

\usepackage{amsmath}
% Inline: the identity $e^{i\pi} + 1 = 0$.
\begin{equation}
  \frac{\partial f}{\partial x} = 2x
\end{equation}
\begin{align}
  a &= b + c \\
    &= d
\end{align}

Use \frac{a}{b} for fractions, x^{2} for superscripts, x_{i} for subscripts, and \sum, \int, \sqrt{} for common operators.

Frequently asked questions

What is the difference between equation and align?

equation is for a single numbered equation; align is for multiple equations aligned at a chosen point (the &), each numbered unless you use align*.

How do I write an unnumbered equation?

Use the starred version: \begin{equation*} ... \end{equation*}, or use \[ ... \] for quick display math.

How do I write a fraction in LaTeX?

Use \frac{numerator}{denominator}, e.g. \frac{1}{2}. For inline fractions in text, \tfrac gives a smaller, text-sized fraction.

Try this in LetX now

Open the editor, paste the example, and compile in 1–2 seconds — free, in your browser.

Start Writing Free