# Variable Definition

In Mathematics, some alphabets can be seen in an equation that **represents unknown values**. All those alphabets that are representing **unknown quantities** are called **variables**. These are mainly used in **Algebraic Expressions**.

**Note:**

You can read about Expression and **Equation** here.

**For example**, In

3x – 7 = 12

is a variable because it is representing an unknown value.

**Table of Contents**

## Types of Variables

There are two main types of variables in Mathematics. Let us show you what are those types and how they are different from each other.

**Dependent Variables**: A variable whose value**depends**on**another variable**of the same equation is called the**dependent variable**.- Represents all the numbers given in the set
**Independent variables:**A**variable**whose value**doesn’t depend**on any other**variable**of the equation is called an**independent variable**.

**Note:**

Read about **Dependent** and **Independent variables** here.

You can understand these types by understanding the following table

Independent Variable,"x" |
Dependent Variable, y = 2x -3 |

2 | 1 |

3 | 3 |

4 | 5 |

5 | 7 |

As we can see the change in the value of **“x”** is changing the value of **“y”**. It means that **“x”** is an **independent** variable while **“y”** is a **dependent variable**.

### Other parts of an equation

An equation doesn’t include variables only but it has other parts too. Here are those parts with their definitions.

**Constant:**All those numbers that**don’t change their values**, in any case, are called Constants. For example, 5 is a constant in this equation**3x = 5****Operator:**It is the the mathematical operator that is used to**connect**different terms in the equation. For example,**“+”**is an operator in this equation**3x + 5 = 0**.**Coefficients:**It is a**number**or**letter**that is**multiplied**by the**variable**given in the equation. For example,**“3”**is the coefficient in this equation**3x + 5 = 0**.

**Note:**

Read about **Operator**, Constant, and Coefficient in detail.

### What is the opposite of the variable in an equation?

In a mathematical expression, the opposite of the variable is called a constant. It is the number that doesn’t change with variations in the equation or variable values. Normally, these are numbers but in some cases, these are also represented by alphabets in addition to variables.

### FAQ's

**What is a variable in Math?**

It is the term that represents the unknown value in any equation.

**What are two types of variables in Math?**

In Mathematics, two types of variables are called the dependent variable and the independent variable.

**How do you identify a variable?**

The term that keeps changing its values with respect to changes in an equation will be a variable.

**Is a variable a number?**

No, a variable can’t be a number because every number has a specific value.

**Is 7 a constant or variable?**

“7” is a constant number because it won’t change its values in any case.