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The distributive property says that $a(b+c) = ab + ac$.
%For short objects, you can simply type parentheses using your keyboard.

The equivalence class of $a$ is $[a]$.
%For short objects, you can simply type square brackets using your keyboard.

The set $A$ is defined to be $A = { 1, 2, 3 }$
%These braces will not appear in the output, since { and } are reserved symbols used for coding.

The set $A$ is defined to be $A = \{ 1, 2, 3 \}$
%If you want to typeset a { or } you must precede each with a \.

My lunch costs \$2.50.
%The symbol $ is also reserved since it is used to indicate MATH MODE.  To typeset a $, precede it with a \.

$$x(\frac{16}{x^2 - 1})$$
%For tall objects, we need to adjust the code to allow for expanded bracketing symbols.

$$x \left( \frac{16}{x^2 - 1} \right)$$
%Here the bracketing symbols will expand to the size of the enclosed objects.

$$A = \{ \frac{1}{2}, \frac{1}{3}, \frac{1}{4} \}$$

$$A = \left\{ \frac{1}{2}, \frac{1}{3}, \frac{1}{4} \right\}$$
%Here the bracketing symbols will expand to the size of the enclosed objects.

$$\left\langle \frac{x}{2}, \frac{y}{2}, \frac{z}{2} \right\rangle$$
%Here the bracketing symbols will expand to the size of the enclosed objects.

$$|-3 + 2| = 1$$

$$| -\frac{3}{2} + \frac{3}{2}| = 0$$

$$\left| -\frac{3}{2} + \frac{3}{2} \right| = 0$$
%Here the bracketing symbols will expand to the size of the enclosed objects.

$$f(x)= \left\{ {x^2} \right.$$
%A left bracketing symbol must be paired with a right bracketing symbol.  
%To hide one or the other, use the command \left. or \right.

$$\left. \frac{dy}{dx} \right|_{x=1}$$

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