# Frequently asked questions - Math

From The Document Foundation Wiki

## How do I align my equations at the equal sign?

Normally Math centers each line of a formula. To align each line at an equal sign you can use **matrix**, as shown in the following example.

Display | Markup |
---|---|

matrix { alignr x+y # {}={} # alignl 2 ## alignr x # {}={} # alignl 2-y } |

The empty braces around the equal sign are necessary because **=** is a binary operator that needs an expression on each side.

The space around the **=** can be reduced by changing the spacing between columns of the matrix:

- Select
**Format > Spacing**. - Click
**Category**and choose**Matrices**from the drop down menu. - Enter 0% for Column spacing.

Sometimes you need to "reserve" some space on the left of the equal sign in multi-line equations. Use **phantom** as shown below.

Header Display | Markup |
---|---|

""3(x+4)-2(x-1)=3 x+12-(2 x-2) newline ""phantom {3(x+4)-2(x-1)}=3 x+12-2 x+2 newline ""phantom {3(x+4)-2(x-1)}=x+14 |

The **phantom** markup indicates that there should be a space the same length as "3(x+4)-2(x-1)". This results in the equal signs lining up properly.

Note: The **""** can also be replaced with **alignl**.