ngaje

\frac{{\displaystyle\sum_{n>0}z^n}}
{{\displaystyle\prod_{1\leqk\leqn}(1-q^k)}}

$\frac{\sum_{n>0}z^n}
{\prod_{1\leqk\leqn}(1-q^k)}$

$\frac{{\displaystyle\sum_{n>0}z^n}}
{{\displaystyle\prod_{1\leqk\leqn}(1-q^k)}}$

$\frac{{\displaystyle\sum\nolimits_{n>0}z^n}}
{{\displaystyle\prod\nolimits_{1\leqk\leqn}(1-q^k)}}$

$$\frac{{\displaystyle\sum\nolimits_{n>0}z^n}}
{{\displaystyle\prod\nolimits_{1\leqk\leqn}(1-q^k)}}$$

Ref:
shot-math-guide.pdf

$$\dfrac{\frac{\huge 7}{r}+\frac{1}{x}}{\frac{3x}{d} + \frac{2t}{5k}}$$

$$\dfrac{\frac\huge{ 7}{r}+\frac{1}{x}}{\frac{3x}{d} + \frac{2t}{5k}}$$


$$\frac{{\displaystyle\frac{7}{r}+\frac{1}{x}}{{\displaystyle\frac{3x}{d} + \frac{2t}{5k}}$$

$$\frac{{\displaystyle\frac{7}{r}+\frac{1}{x}}{{\frac{3x}{d} + \frac{2t}{5k}}$$

$${\tinyExample1}$$

$$\tinyExample1$$

$$\tiny Example 1$$

$$\scriptsize Example 2$$

$$\footnotesize Example 3$$

$$\small Example 4$$

$$\normalsize Example 5$$

$$\large Example 6$$

$$\Large Example 7$$

$$\huge Example 8$$

$$\Huge Example 9$$

\Huge$\Frac{a}{b}$

(\Huge$\Frac{a}{b}$)

Mathmode

$
\begin{equation}
x = a_0 + \frac{1}{\displaystyle a_1
  + \frac{1}{\displaystyle a_2
  + \frac{1}{\displaystyle a_3 + a_4}}}
\end{equation}
$

$
\begin{equation}
x = a_0 + \frac{1}{\displaystyle a_1
  + \frac{1}{\displaystyle a_2
  + \frac{1}{\displaystyle a_3 + a_4}}}
\end{equation}
$

$
\
x = a_0 + \frac{1}{\displaystyle a_1
  + \frac{1}{\displaystyle a_2
  + \frac{1}{\displaystyle a_3 + a_4}}}
\
$$

[[$x^2+y^2=z^2$]]

[[$\mbox{\fontsize{12}{14}\selectfont $x^2+y^2=z^2$}$]]

[[$\mbox{\fontsize{14}{17}\selectfont $x^2+y^2=z^2$}$]]

[[$\mbox{\fontsize{17}{20}\selectfont $x^2+y^2=z^2$}$]]

[[$\mbox{\fontsize{20}{24}\selectfont $x^2+y^2=z^2$}$]]

[[$\mbox{\fontsize{24}{30}\selectfont $x^2+y^2=z^2$}$]]

http://community.wikidot.com/forum/t-5373/how-to-change-the-size-of-formulas

$\DeclareMathSizes{13.82}{14.4}{10}{7}$

$\LaTeX&s=-4$

$latex \LaTeX&s=X$

$\frac{1}{2}=0.5$
$\frac{1}{2}=0.5

$$\tfrac{1}{2} = 0.5$$
http://meta.wikimedia.org/wiki/Help:Displaying_a_formula

$\cfrac{2}{c + \cfrac{2}{d + \cfrac{1}{2}}} = a $

\frac{{\displaystyle\sum_{n>0}z^n}}
{{\displaystyle\prod_{1\leqk\leqn}(1-q^k)}}

$\frac{\sum_{n>0}z^n}
{\prod_{1\leqk\leqn}(1-q^k)}$

$\frac{{\displaystyle\sum_{n>0}z^n}}
{{\displaystyle\prod_{1\leqk\leqn}(1-q^k)}}$

$\frac{{\displaystyle\sum\nolimits_{n>0}z^n}}
{{\displaystyle\prod\nolimits_{1\leqk\leqn}(1-q^k)}}$

$$\frac{{\displaystyle\sum\nolimits_{n>0}z^n}}
{{\displaystyle\prod\nolimits_{1\leqk\leqn}(1-q^k)}}$$

Ref:
shot-math-guide.pdf

$$\dfrac{\frac{7}{r}+\frac{1}{x}}{\frac{3x}{d} + \frac{2t}{5k}}$$

$$\frac{{\displaystyle\frac{7}{r}+\frac{1}{x}}{{\displaystyle\frac{3x}{d} + \frac{2t}{5k}}$$

$$\frac{{\displaystyle\frac{7}{r}+\frac{1}{x}}{{\frac{3x}{d} + \frac{2t}{5k}}$$

Evaluate the sum $\displaystyle\sum_{i=0}^n i^3$.

Evaluate the sum $$\displaystyle\sum_{i=0}^n i^3$$

Evaluate the sum $$\sum_{i=0}^n i^3$$


http://www.artofproblemsolving.com/LaTeX/AoPS_L_BasicMath.php

$$
\frac{1}{\displaystyle 1+
\frac{1}{\displaystyle 2+
\frac{1}{\displaystyle 3+x}}} +
\frac{1}{1+\frac{1}{2+\frac{1}{3+x}}}
$$

$$\frac{2+\frac{5}{x}}{7x + 1}$$

$$\frac{2+\frac{5}{\displaystyle x}}{7x + 1}$$

$$\frac{2+\frac{\displaystyle 5}{\displaystyle x}}{7x + 1}$$

\[
 x + 5 = -3
\]
http://crab.rutgers.edu/~karel/latex/class4/class4.html

\[
\frac{\frac{1}{x}+\frac{1}{y}}{y-z}
\]

$latex \[
\frac{y+z/2}{y^{2}+1}
\] $

\[
    \frac{y+z/2}{y^{2}+1}
\]

http://www.seanet.com/~bradbell/omhelp/frac.htm

$$\begin{equation}
E = mc^2
\end{1}$$
http://answers.yahoo.com/question/index?qid=20070929120648AAiUq1U

$$\begin{align}
2x^2 + 3(x-1)(x-2) & = 2x^2 + 3(x^2-3x+2)\\
\nonumber &= 2x^2 + 3x^2 - 9x + 6\\
&= 5x^2 - 9x + 6
\end{align}$$