Expanding (A-B)^2: Simple Algebraic Formula - Blog Feed Letters

Expanding (A-B)^2: Simple Algebraic Formula

by Yash

When it comes to mathematics, algebra plays a vital role in solving equations and understanding the relationships between numbers and variables. One common algebraic expression that students frequently encounter is the expansion of the square of a binomial, expressed as (A-B)^2. Understanding how to expand this expression is crucial for simplifying equations and solving problems in various mathematical contexts. In this article, we will dive into the intricacies of expanding (A-B)^2, providing a detailed step-by-step guide along with examples to enhance your understanding.

Introduction to (A-B)^2 Expansion

Before delving into the process of expanding (A-B)^2, it’s essential to grasp the concept behind it. The expression (A-B)^2 represents the square of the binomial (A-B). When we expand this expression, we are essentially multiplying the binomial by itself. The expanded form of (A-B)^2 will result in a trinomial, comprising three terms. This expansion is a fundamental algebraic skill that forms the basis for more advanced mathematical manipulations.

Step-by-Step Guide to Expanding (A-B)^2

Expanding (A-B)^2 involves applying the formula for squaring a binomial. The general formula for squaring a binomial (A-B)^2 is as follows:

(A-B)^2 = A^2 – 2AB + B^2

Let’s break down the expansion process step by step:

Step 1: Square the First Term

The first term in the expansion is the square of the first term in the binomial, which is A^2.

Step 2: Multiply the Two Terms and Double the Result

The middle term in the expansion is obtained by multiplying the two terms in the binomial and then doubling the result. In this case, it is -2AB, as we are multiplying -A and B.

Step 3: Square the Second Term

The last term in the expansion is the square of the second term in the binomial, which is B^2.

Example of (A-B)^2 Expansion

Let’s illustrate the expansion of (A-B)^2 with a concrete example:

Given: (2x-3)^2

Using the formula (A-B)^2 = A^2 – 2AB + B^2, we can expand the expression as follows:

(2x-3)^2 = (2x)^2 – 2(2x)(3) + (-3)^2
= 4x^2 – 12x + 9

Therefore, the expansion of (2x-3)^2 is 4x^2 – 12x + 9.

Benefits of Mastering (A-B)^2 Expansion

Understanding how to expand (A-B)^2 has several benefits in the realm of algebra and mathematics. Some of the key advantages include:

  1. Simplification of Equations: Expanding (A-B)^2 allows for the simplification of complex algebraic expressions, making it easier to solve equations.

  2. Enhanced Problem-Solving Skills: Proficiency in expanding (A-B)^2 enables students to tackle a wide range of mathematical problems with confidence.

  3. Foundation for Further Learning: Mastery of basic algebraic manipulations sets a strong foundation for more advanced mathematical concepts.


The expansion of (A-B)^2 is a fundamental algebraic skill that forms the basis for many mathematical operations. By following the steps outlined in this article and practicing with various examples, you can enhance your algebraic proficiency and problem-solving abilities. Remember to apply the formula (A-B)^2 = A^2 – 2AB + B^2 diligently to expand similar expressions in the future.

Frequently Asked Questions (FAQs)

Q1: Why is expanding (A-B)^2 important in algebra?
A1: Expanding (A-B)^2 is essential as it helps in simplifying expressions, solving equations, and developing foundational algebraic skills.

Q2: Can the formula for expanding (A-B)^2 be generalized for higher powers?
A2: Yes, the formula for expanding (A-B)^2 can be extended to higher powers using the binomial theorem.

Q3: How can I practice expanding (A-B)^2 to improve my skills?
A3: You can practice by solving numerous problems involving the expansion of (A-B)^2, gradually increasing the complexity of the expressions.

Q4: Are there any online resources available to further explore (A-B)^2 expansion?
A4: Yes, there are several online platforms offering tutorials, practice problems, and interactive tools to enhance your understanding of algebraic concepts.

Q5: What are some real-world applications of understanding (A-B)^2 expansion?
A5: Understanding (A-B)^2 expansion is beneficial in areas such as physics, engineering, finance, and computer science, where mathematical modeling and calculations are involved.

Whether you are a student learning algebra or someone looking to refresh their mathematical skills, mastering the expansion of (A-B)^2 is a valuable asset. By following the guidelines and examples provided in this article, you can confidently navigate through algebraic expressions and equations with ease. Practicing regularly and exploring further applications of this concept will deepen your understanding of algebra and its practical implications.

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