If n ≤ 4 and 2 ≤ m ≤ n ≤ 5, then what is the greatest possible value of (n - m)(n + m)?

Question

Option 1: 9

Option 2: 21

Option 3: 12

Option 4: None of these

AfterBoards · Accepted Answer

The answer is '12'. View full solution:

If $n \leq 4$ and $2 \leq m \leq n \leq 5,$ then what is the greatest possible value of $(n - m)(n + m)?$