When a problem is presented to us in writing, we can convert it into mathematical language (also called algebraic language) by transforming it into an algebraic expression. But** what are algebraic expressions?**

**Variable:** This is a letter that represents a numerical value, for example **$X$** or **$Y$**. This letter refers to an unknown numerical value that we must work out. For example: if **$X+5=8$**, then we can conclude that the numerical value of **$X$** is **$3$**.

An algebraic expression is a combination of numbers and letters (representing unknown numbers) that includes operations such as addition, subtraction, multiplication, division, etc.

Each element of an algebraic expression is called an **algebraic term**, be it a **variable**, a **constant**, or a combination of a **coefficient** and one or more variables. If the expression contains only one term, it is known as a **monomial**, while those that contain two or more terms are **polynomials**.

There is no limitation to the amount of constant numbers, unknown variables, or operations that can appear in an algebraic expression. In addition, there does not always have to be a variable in the algebraic expression, although it will always have a certain numerical value.