Question

Factorise completely 45m² - 5n².​

Answer 1

Answer:

5(3m+n)(3m - n)

Step-by-step explanation:

Factorize:

 First take the common factor '5' from both the terms.

    45m² - 5n² = 9*5*m² - 5n²

                        = 5*(9m² - n²)

                        = 5*( [3m]² - n²)

$\sf \boxed{\bf use \ the \ identity: \ a^2 - b^2 = (a+b)(a-b)}$

Here, a = 3m and b = n

                          = 5* [ (3m + n)(3m - n)]

                          = 5 *(3m + n)*(3m - n)