An equation in mathematics is defined as an established equality between two expressions, in which there can be one or more unknowns that must be solved.

The equations are used to solve different mathematical, geometric, chemical, physical or any other problems that have applications both in everyday life and in the research and development of scientific projects.

Equations may have one or more unknowns, and it may also be the case that they have no solution or that more than one solution is possible.

## Parts of an equation

The equations are made up of different elements. Let’s look at each of them.

Each equation has two **members** , and these are separated by using the equal sign (=).

Each member is made up of **terms** , which correspond to each of the monomials.

The **values** of each monomial of the equation can be of different tenor. For example:

- constants;
- coefficients;
- variables;
- functions;

The **unknowns** , that is, the values you want to find, are represented by letters. Let’s see an example of an equation.

Algebraic equation example

## Types of equations

There are different types of equations according to their function. Let’s know what they are.

### 1. Algebraic equations

The algebraic equations, which are the fundamental ones, are classified or subdivided into the different types described below.

#### to. First-degree equations or linear equations

They are those that involve one or more variables to the first power and do not present a product between variables.

**For example** : *ax + b = 0*

See also: First-degree equation

#### b. Quadratic equations or quadratic equations

In this type of equation, the unknown term is squared.

**For example** : *ax *^{2}* + bx + c = 0*

#### c. Third-degree equations or cubic equations

In this type of equation, the unknown term is cubed.

**For example** : *ax *^{3}* + bx *^{2}* + cx + d = 0*

#### d. 4th degree equations

Those in which a, b, c and d are numbers that are part of a body that can be ℝ or ℂ.

**For example** : *ax *^{4}* + bx *^{3}* + cx *^{2}* + dx + e = 0*

### 2. Transcendent equations

They are a type of equation that cannot be solved only by algebraic operations, that is, when it includes at least one non-algebraic function.

**For example,**

### 3. Functional equations

They are those whose unknown is a function of a variable.

**For example,**

### 4. Integral equations

The one in which the unknown function is found in the integrand.

### 5. Differential equations

Those that relate a function to its derivatives.