CSATNumber System & SeriesFactorization2020

How many pairs of natural numbers are there such that the difference of whose squares is 63?

A

3

B

4

C

5

D

2

Correct Answer: Option A

Explanation

1. **Identify the Pattern**: The expression 'difference of squares' immediately points to the identity $x^2 - y^2 = (x - y)(x + y)$. This

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