Question

find the product by using suitable identity(x^2+4) (x^2-4)

Answer 1

(a+b)(a-b)=a^2-b^2
(x^2+4)(x^2-4)=(x^2)^2-(4)^2
=x^4-16

Answer 2

(x'2+4)(x'2-4)
=x'2'2-4'2
=x'4-16


the sign ' means to the power here

hope it helps