Class 9 Maths - Important Identities (#class9Maths)(#eduvictors)

Class 9 Maths - Important Identities

(a+b)² = a² + 2ab+ b²

(a–b)² = a² –2ab + b²

a² – b² = (a+b)(a–b)

(x+a)(x+b) = x²  + (a+b)x + ab

(a+b+c)² = a² +b² +c² + 2ab + 2bc + 2ca

(a+b)³ =a³ + b³ + 3ab(a+b)

(a–b)³ =a³ – b³ – 3ab(a–b)

a³ +b³ +c³ – 3abc = (a+b+c)(a² +b² +c² –ab –bc –ca)

(a+b)⁴ = a⁴ + 4a³b + 6a²b² +4ab³ + b⁴

a² –b² =(a+b)(a–b)

a³ –b³ =(a–b)(a² + ab + b²)

a³ + b³ = (a+b)(a² –ab + b²)

a⁴ –b⁴ = (a² –b²)(a² +b²)

👉See Also:

Maths Resources

Maths Symbols

Special Constants

NCERT Polynomials - Exercise 2.1
Polynomials - Exercise 2.2 (NCERT)
Polynomials - Exercise 2.3 (NCERT)
Polynomials - Exercise 2.4 (NCERT) 
Polynomials - Exercise 2.5 (NCERT) + Exercise 4.1(R D Sharma)
Polynomials (Important Points To Remember)