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(a + b)³ Formula: A Plus B Whole Cube Formula

(a + b)³ Formula, also called the a plus b whole cube formula, helps expand the cube of a sum quickly. Written as a³ + 3a²b + 3ab² + b³, it makes calculations with numbers, variables, and algebra simpler, allowing students to solve problems faster, understand concepts better, and gain confidence in algebra.
authorImageShivam Singh25 Oct, 2025
(a + b)³ Formula

The (a + b)³ formula, also known as the a plus b whole cube formula, is a fundamental algebraic identity used to expand the cube of the sum of two terms. It expresses the expansion as (a+b)3=a3+3a2b+3ab2+b3This formula helps to quickly expand expressions without multiplying the binomial three times. It breaks the cube of a sum into the sum of the cubes of each term plus three times the product of the square of one term and the other, making algebraic calculations easier and faster. Understanding this formula is a key step in mastering binomial expansions and simplifies solving numerous algebra problems.

(a+b)^3 Formula

The formula (a+b)3 is used to expand the cube of a binomial expression. It means the expression (a+b) multiplied by itself three times. The expanded form is a3+3a2b+3ab2+b3. This formula helps in simplifying expressions without multiplying the binomial three times. It is widely used in algebra to solve problems involving cubes.

(a+b)3 Formula

The expression (a+b)3 can be written as a3+3a2b+3ab2+b3. This gives the cube of the sum of two terms. Each term in the expansion follows a pattern based on powers of aa and bb, combined with coefficients from the binomial theorem. Knowing this helps in quick calculation and algebraic manipulations.

(a+b)^3 Formula Expansion

Expanding (a+b)3 means writing it as the sum of four terms: a3a3, 3a2b3a2b, 3ab23ab2, and b3b3. This expansion comes from multiplying (a+b) thrice and combining like terms. This formula saves time and effort while solving algebraic equations involving cubic expressions.

(a+b)3 Formula Solution

To solve the (a+b)3 formula, we use the identity: (a+b)3=a3+3a2b+3ab2+b3. Plug the values of aa and bb into this formula to find the expanded expression. This method is faster than multiplying the binomial multiple times and helps in solving various problems involving cubic expressions.

Formula of (a+b)3

The formula for (a+b)3 is a key algebraic identity given by a3+3a2b+3ab2+b3. It represents the cube of the sum of two terms and is derived from the binomial theorem. This formula is very helpful in mathematics to expand expressions involving cubes without lengthy multiplication.

A Plus B Cube Formula

The "a plus b cube" formula refers to (a+b)3, which equals a3+3a2b+3ab2+b3. It gives the expression of the cube of the sum of aa and bb. This formula is widely applied in algebra to simplify and expand binomial cubes in an easy way.

What is (a + b)³ Formula?

(a + b)³ formula, also called the a plus b whole cube formula, is an important formula in mathematics. It helps us expand expressions where a number or variable is added to another number or variable and raised to the power of three. Learning this formula ab 3 makes solving algebra problems easier for students.

The (a + b)³ formula is written as:

(a + b)³ = a³ + 3a²b + 3ab² + b³

Here:

  • a³ is the cube of the first term

  • b³ is the cube of the second term

  • 3a²b and 3ab² are the middle terms, which include both a and b

Read more: Construction in Maths

(a + b)³ Formula Breakdown

Understanding (a+b)^3  formula becomes much easier when we break it into simple steps. This helps students see how each part of the expression contributes to the final result. By following these steps carefully, you can expand any cube of a sum quickly and correctly, making algebra problems much simpler and faster to solve. Let’s break down the formula (a + b)³ step by step:

1. Start with (a + b) × (a + b) × (a + b)

2. Multiply the first two brackets:

   (a + b) × (a + b) = a² + 2ab + b²

3. Now multiply this result with the third bracket (a + b):

   (a² + 2ab + b²) × (a + b) = a³ + 3a²b + 3ab² + b³

Step-by-Step Method to Use (a + b)³ Formula

In order to effectively apply the whole cube formula for a plus b, it can be proceeded through a specific step-by-step approach. With practice of each step, students can expand any sum of a whole cube easily and avoid errors. Follow these steps to use the a plus b whole cube formula:

1. Determine what a and b represent in the expression.

2. Use the formula (a+b)³ = a³ + 3a²b + 3ab² + b³

3. Substitute the values for a and b accordingly.

4. Simplify and state your answer.

Example 1: Expand (2 + 3)³

Step 1: a = 2, b = 3  

Step 2: Use formula: a³ + 3a²b + 3ab² + b³  

Step 3: Substitute values: 2³ + 3×2²×3 + 3×2×3² + 3³  

Step 4: Calculate: 8 + 36 + 54 + 27 = 125  

Answer: (2 + 3)³ = 125

Example 2: Expand (x + 2)³

Step 1: a = x, b = 2  

Step 2: Use formula: a³ + 3a²b + 3ab² + b³  

Step 3: Substitute values: x³ + 3×x²×2 + 3×x×2² + 2³  

Step 4: Simplify: x³ + 6x² + 12x + 

Here, we used the formula ab³ to expand an expression with a variable.

Example 3: Expand (3 + y)³

Step 1: a = 3, b = y  

Step 2: Use formula: a³ + 3a²b + 3ab² + b³  

Step 3: Substitute values: 3³ + 3×3²×y + 3×3×y² + y³  

Step 4: Simplify: 27 + 27y + 9y² + y³  

Read More: Successor and Predecessor

Why is (a + b)³ Formula Important?

Understanding the (a + b)³ formula is of wide importance as it enables students to solve algebra problems more quickly and accurately. When students learn the formula for ab³, they have a tool they can use to expand cubes of sums without repeating long multiplication steps. The a plus b whole cube formula also gives students confidence in mathematics because they will have more knowledge and skill when dealing with numbers, variables, or word problems related to cubes. The a plus b whole cube formula is important because it:

  • Saves time when solving algebra problems

  • Helps students avoid mistakes in multiplying

  • Builds confidence in mathematics

  • Used in higher-level mathematics, volume calculations, equations, and word problems

Read More: Median - Formula, Meaning, Example

Tips to Remember (a + b)³ Formula

Remembering the (a + b)³ formula becomes easier when you follow a few simple tips. By keeping these points in mind, students can quickly recall the formula while solving problems. These tips help in avoiding mistakes and make algebra faster and more fun for practice and exams.

  1. The first term is always a³

  2. The last term is always b³

  3. The middle terms are always multiplied by 3

  4. Practice small examples first, such as (1 + 2)³ or (x + 1)³

With consistent practice, the formula of ab³ becomes easy to remember and apply.

Real Life (a + b)³ Formula Examples

The (a + b)³ formula is not just for classroom problems; it can also be applied in real-life situations. Understanding how to use this formula helps students solve practical problems, like calculating volumes, combining quantities, or working with measurements, making math more useful and easier to relate to everyday life. Below are some real-life examples of the formula of ab 3:

  • Volume Calculation: If the length, width, and height increase by a certain amount, you can use the formula to calculate total volume.

  • Money Problems: Adding two amounts and finding their cube can be calculated easily with the formula.

  • Math Puzzles: Many school-level algebra puzzles require expanding cubes of sums.

 Also Read: Brackets in Maths

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A plus B whole cube formula FAQs

What is the a plus b whole cube formula?

It is (a + b)³ = a³ + 3a²b + 3ab² + b³, used to expand the cube of a sum.

How is the formula ab cube used in calculations?

Identify a and b, substitute into a³ + 3a²b + 3ab² + b³, and simplify.

Can the a plus b whole cube formula be used for variables?

Yes, it works for numbers, letters, or both together.

Why is it called a plus b whole cube formula?

Because it represents the cube of the sum of two terms: (a + b)³
Curious Jr By PW

Curious Jr By PW

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