Formula deep page
Key Identities
(a+b)² = a²+2ab+b²
(a-b)² = a²-2ab+b²
(a+b)(a-b) = a²-b²
This formula belongs to the chapter "Polynomials" in Class 9 Mathematics. Use it after identifying the right variables, matching the chapter context, and writing the substitution clearly.
How to use it
- Identify the quantity you need to find.
- Check the related variables and units from the question.
- Substitute values carefully into the formula.
- Simplify step by step and write the final statement.
Worked cue
(x+3)² = x²+6x+9 | (2x-5)(2x+5) = 4x²-25