SOLUTION: Write an indirect proof for, Given: n squared is even Prove: n squared is divisible by 4

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Question 387192: Write an indirect proof for,
Given: n squared is even
Prove: n squared is divisible by 4
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
The idea is that if n%5E2 is even, then n is even (you can prove this by contraposition). So n=2k for some integer k.


So n%5E2=%282k%29%5E2=4k%5E2. So because n%5E2=4k%5E2, this means that n%5E2 is a multiple of 4.