Question

factorise the following by using suitable identity ( l² - 21m + m² ) - n² ​

Answer 1

Answer:

(l²-2lm-m²)-n²

(a-b)²=a²-2ab+b²

(l-m)²-(n)²

(a²-b²)=(a+b)(a-b)

(l-m-n)(l-m+n)

hope it helps you and don't forget to follow me

Answer 2

Step-by-step explanation:

photo uploaded

ans-(l-m-n)(l-m+n)