**Equations**

**What is an equation?**

**An equation is the equality between two mathematical expressions in which at least one variable or unknown is involved**. This equality may or may not be verified and, if there is, occurs for a value of the variable or a given set of values assigned to its variables.

Every equation will have the symbol **«=»** which means equality and which is used to represent the equality of two mathematical or algebraic expressions. The expressions on both sides of the **equal sign** are called the **«left side» and the «right side» of the equation**.

**Examples of Equations:**

Note below **5 examples of equations**:

- x = 2
- 2x + 4 = 10
- 4x
^{2}– y = 3x – 5 - 3x
^{5}+ 2xy^{3}= 10 - 7x
^{5}+ xy^{3}+ z = x³ + 5x²y² + 8

Note that **equations** 1 and 2 have the variable «x» and the equations in examples 3, 4 and 5 to «x» and «y».

Understood