Question

What is the factored form of a2 – 121?

Answer 1

the factor used form will be
(a+11)(a-11)
using the identity a^2-b^2=(a+b)(a-b)

Answer 2

a²-121
⇒a²-11² 
⇒(a+11)(a-11) { by using identity a²-b²=(a+b)(a-b) }