Algebraic Expressions, Monomials, Polynomials, Formulas, and Mathematical Identities

Algebraic expressions are fundamental concepts in mathematics used to represent numerical relationships and solve various problems. In this article, we explore algebraic expressions, monomials, and polynomials, review commonly used mathematical formulas, and explain all major mathematical identities in a clear and practical way.

Algebraic ExpressionPolynomialMathematical Identities

~2 min read • Updated Jan 31, 2026

1. What Is an Algebraic Expression?


An Algebraic Expression is a combination of numbers, variables, and mathematical operators such as addition, subtraction, multiplication, and division. Variables like x, y, or a represent unknown values.


Examples of Algebraic Expressions:

3x + 5
2a - 7
x^2 + 4x + 1

2. What Is a Monomial?


A Monomial is a type of Algebraic Expression that consists of a single term. It contains only multiplication between numbers and variables.


Examples of Monomials:

5x
-3a^2
7xy

3. What Is a Polynomial?


A Polynomial is formed by combining two or more Monomials using addition or subtraction.


Examples of Polynomials:

x + 3
2x^2 - 5x + 1
a^2 + ab + b^2

4. Degree of Algebraic Expressions


The Degree of an algebraic expression is the highest power of the variable in the expression.


  • The degree of 5x is 1
  • The degree of 3x^2 + x is 2
  • The degree of x^3 - 2x^2 + x is 3

5. Common Mathematical Formulas


Many calculations in algebra rely on important Mathematical Formulas.


Formula Examples:

a + a = 2a
a × a = a^2
(a + b) ÷ c = a/c + b/c

6. Important Mathematical Identities


Mathematical Identities are equations that help simplify and solve algebraic expressions efficiently.


Square of a Sum:

(a + b)^2 = a^2 + 2ab + b^2

Square of a Difference:

(a - b)^2 = a^2 - 2ab + b^2

Product of Sum and Difference:

(a + b)(a - b) = a^2 - b^2

Cube of a Sum:

(a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3

Cube of a Difference:

(a - b)^3 = a^3 - 3a^2b + 3ab^2 - b^3

7. Applications of Algebraic Expressions and Identities


Algebraic Expressions and Mathematical Identities are widely used in solving equations, simplifying calculations, physics, engineering, and many real-world problems.


Conclusion


Understanding Algebraic Expressions, Monomials, Polynomials, and Mathematical Identities forms the foundation of algebra. Mastering these concepts makes solving complex mathematical problems faster and more efficient.


Written & researched by Dr. Shahin Siami