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Difference of Squares Calculator.
Calculates the difference between two squares and shows the factored form (a² - b² = (a + b)(a - b)).
Your inputs
How it works
- 1
Enter the values for a and b.
- 2
Square each value: a² and b².
- 3
Subtract b² from a² to get the difference.
- 4
The factored form is (a + b)(a - b), which equals the same result.
a^2 - b^2Frequently asked questions
What is the difference of squares formula?
The formula is a² - b² = (a + b)(a - b). It shows that the difference of two squares can be factored into the product of their sum and difference.
Can a and b be negative?
Yes, the formula works for any real numbers. For example, (-7)² - 2² = 49 - 4 = 45, and (-7 + 2)(-7 - 2) = (-5)(-9) = 45.
What if a equals b?
If a = b, then a² - b² = 0, and the factored form (a + b)(a - b) also equals 0 because (a - b) = 0.
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Results
Formula checkedEstimate for general guidance only — verify important decisions with an appropriate professional.
How it works
Calculates the difference between two squares and shows the factored form (a² - b² = (a + b)(a - b)).
- Enter the values for a and b.
- Square each value: a² and b².
- Subtract b² from a² to get the difference.
- The factored form is (a + b)(a - b), which equals the same result.
Formulas
The math behind this calculator, written out so you can verify the result.
Difference of Squares
This identity states that the difference between two squares equals the product of the sum and difference of the two numbers.
Example:
Input: a = 5, b = 3
Calculation: 5² - 3² = 25 - 9 = 16, and (5+3)(5-3) = 8 × 2 = 16
Result: 16
Real-world use cases
Where this calculation shows up in everyday life.
Simplifying algebraic expressions
Factor expressions like x² - 9 quickly into (x + 3)(x - 3).
Example: x² - 9 = (x + 3)(x - 3)
Mental math
Compute differences of squares without a calculator, e.g., 99² - 1² = (99+1)(99-1) = 100 × 98 = 9800.
Example: 99² - 1² = 9800
Solving equations
Use the identity to solve quadratic equations that are in the form a² = b².
Example: x² = 16 → x² - 16 = 0 → (x+4)(x-4)=0 → x = ±4
Tips and common mistakes
Tips
- Remember the identity: a² - b² = (a + b)(a - b).
- Check your result by expanding (a + b)(a - b) to see if you get a² - b².
- The formula works for any real numbers, including fractions and decimals.
- Use the factored form to simplify calculations when a and b are large.
Common Mistakes to Avoid
- Forgetting that a² - b² is not equal to (a - b)². (a - b)² = a² - 2ab + b².
- Confusing the order: a² - b² is not the same as b² - a² unless you factor out a negative.
- When a and b are negative, forgetting that squaring makes them positive.
Assumptions and limitations
- Use the stated inputs and units.
- Results are estimates for planning and education.
- Check measurements and source data before making an important decision.