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I am trying to proof the following question.

If a is an integer, divisible by 4, then a is the difference of two perfect squares

now by the definition of divisibility if 4 divides a then there is a natural number k such that

a = 4k

Can someone how should I do it with direct proof by using if then technique?

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# Direct proof by using if then technique

**Physics Forums | Science Articles, Homework Help, Discussion**