Systems of equations can also be represented using matrices. A **matrix** is a rectangular grid full of numbers, such as

The great thing about a matrix is that it keeps all those floating numbers trapped inside a box, so they can't escape. It might need to plug up a couple of holes at the top and bottom, but it's better than nothing.

The word "matrix'' has many interesting meanings. There's a movie called *The Matrix*. (We're not counting the "sequels," and you can't make us.) There's also a matrix in the science fiction television series *Dr. Who*. There was a character named "Dot Matrix" in the movie *Spaceballs*. We could go on, but we're getting tired of all the linking.

Anyway, back to math. The system of equations

could also be written as a matrix equation:

The subject of linear algebra deals with ways to solve matrix equations, as well as various other things relating to matrices. For example, if you get married one day, you may want to have a Matrix of Honor by your side.

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