Equation Defintion

In Mathematics, an equation shows that two expressions are equal to each other. An equation, in Algebra, can involve multiple variables, constants, and terms. For example, 2x + 4 = 9 is an equation as it is showing that 2x + 4 and 9 (both are expressions) are equal to each other.


Read about Expressions, Variables, Constant, and Terms here.

Representation of an equation

To represent equality between two terms or expressions, a sign of “=” is put between those terms. It means that “=” is the sign that represents the overall term as an equation.

For example, , if we have two expressions 5x + 7 and 2y + 11, and want to show them in the form of an equation, we will put “=” between them as shown below.

5x + 7 = 2y + 11

Parts of an equation

As mentioned above, an equation is a connection between different expressions. An expression is also made from different terms. It means that an equation has multiple parts involving those of an expression too. Here are the major parts of an equation.

  • Variable
  • Term
  • Operator
  • Sign of equality
  • Constant

An equation can involve any of these parts but the sign of equality will always be there as it is the basic condition.


Read about Operator here.

Types of equations

Depending on the degree of the variable, equations can be divided into three major types. Here we have enlisted those types with a brief discussion.

Linear equations: All those equations in which the maximum degree of the variable is “1” are called linear equations. For example, 2x + 4 = 9 is a linear equation because “x” has a maximum degree of “1”.


Read about Linear equations here.

Quadratic equations: The equations in which the maximum degree of variable is “2” will be termed quadratic equations. For example, 〖2x〗^2-3x+17=12 is a quadratic equation because the degree of “x” is “2”.


Read about Quadratic equations here.

Cubic equations: Those equations in which the variable has a maximum degree of “3” are called cubic equations. For example, 〖12y〗^3 〖+ 2y〗^2-3y+127=162 is a cubic equation because the maximum power of “y” is “3”.


Read about Cubic equations here.

Are expression and equation the same?

No, these are not the same. An expression is the collection of different terms without any equality or inequality sign. For example, 3x + 15 is an expression. On the other side, the equation shows that the given expressions are equal to each other by putting a sign of equality between them.

How can we solve equations in Mathematics?

We can solve Mathematical equations by following all basic operators like addition, Subtraction, Division, and Multiplication. It depends on the operators involved in an equation and the degree of the equation.


Read about Addition, Subtraction, Multiplication, and Division here.

Fun Facts about Equations

  • All equations have specific graphs to relate different variables.
  • A linear equation always gives a straight-line graph
  • The values that make an equation true are called the roots of the equation.


Define an equation with an example.

An equation shows that two given expressions are equal to each other. For example, 3y + 17 = 67 is an equation it shows that two expressions are equal.

What are the three main types of equations?

Depending on the degree of the variable, equations have three major types. Here are those types:

  • Linear equations
  • Quadratic equations
  • Cubic equations

Can we write the equation of a circle?

Yes, we can write an equation of a circle. In fact, all Geometrical diagrams have specific equations to get their solution.