Question

If k = (n + 2)(n – 2), where n is an integer greater than 2, what is the value of k ? (1) k is the product of two primes. (2) k < 100

Answer 1

The answer is k=77

Explanation:

It is given that n is an integer and greater than 2. Let us simplify k = (n + 2)(n – 2) to k=n^2-4.

In (1) it is stated that k is the product of two primes and in (2) it is stated that k<100. To solve the question we need to consider both cases (1) and (2).

Let say n=9 then k=n^2-4 becomes k=81-4=77. Well, 77 is the product of two prime numbers 7 and 11 (77=7*11). The answer is k=77