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Prove that an integer x is odd if x=2k+1 for some integer k

username1226161

where do I start with this?

Reply 1

username1560589

Original post by lightningdoritos

where do I start with this?

What's the definition of odd?

Reply 2

Blue Maths

2k is an even number, because it is a multiple of 2. Then +1 to your 2k (even number) so you will then get an odd number. Hence, any even number (2k) +1 will make an odd number, x... I think that's what you want

Reply 3

Gome44

Original post by lightningdoritos

where do I start with this?

You could probably use induction if you really wanted to, but i think its overkill.

Anyway, isn't that just the definition of an odd number, it would be like trying to prove i=sqrt(-1)