Question

Factorise :
(i) p2-9​

Answer 1

Refer to the attachment for your answer

Answer 2

✩The method used to break down the factors, or numbers that multiply to form another number is called factorisation.

☞Correct Question:

✩Factorise :

(i) p² - 9

☞Solution:

p² - 9 = p² - 3²

Use identity a² - b²

a² - b² = (a + b) (a - b)

=> p² - 3²

=> p² - (3)² = (p +3) (p - 3)

☞Standard Algebraic 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)