## ::Algebra

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**Algebra**::''a'' Theory::**algebra** Numbers::which Group::''b'' Equation::title First::element

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**Algebra** (from Arabic and Farsi *"al-jabr"* meaning "reunion of broken parts"<ref>{{#invoke:citation/CS1|citation
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Elementary algebra differs from arithmetic in the use of abstractions, such as using letters to stand for numbers that are either unknown or allowed to take on many values.<ref name=citeboyer /> For example, in <math>x + 2 = 5</math> the letter <math>x</math> is unknown, but the law of inverses can be used to discover its value: <math>x=3</math>. In <math>E=mc^2</math>, the letters <math>E</math> and <math>m</math> are variables, and the letter <math>c</math> is a constant. Algebra gives methods for solving equations and expressing formulas that are much easier (for those who know how to use them) than the older method of writing everything out in words.

The word *algebra* is also used in certain specialized ways. A special kind of mathematical object in abstract algebra is called an "algebra", and the word is used, for example, in the phrases linear algebra and algebraic topology.

A mathematician who does research in algebra is called an **algebraist**.

**Algebra sections**

Intro Etymology Different meanings of \"algebra\" Algebra as a branch of mathematics History Areas of mathematics with the word algebra in their name Elementary algebra Abstract algebra See also Notes References External links

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