Question

Which of the following numbers can be written as the difference between two perfect squares? a) 218 b) 436 c) 1234 d) 2020





Answer pls ​

Answer 1

Answer:

Since a - b = 1, b = a-1, so b = \frac{p+1}{2} - 1 = \frac{p-1}{2}. Thus, any odd prime can be written as the difference of two squares. Any square number n can also be written as the difference of two squares, by taking a = \sqrt{n} and b = 0.