I have a result and not sure what kind of proof to use to explain it.It's :
let x be an integer, x^3 is even iff x is even
thank you!
$\displaystyle x = 2k \implies x^3 = (2k)^3 = 2^3k^3 = 2 \cdot 2^2k^3 = 2(4k^3)$. if you are at the level where you are doing proofs like this, this is not a question you should be asking.
yes it isWould this be a direct proof?
for the second result, use the contrapositive. Plato gave you a hint for this
Then you know nothing about mathematics!
Mathematics is only about proofs.
Numbers have almost nothing to do with mathematics.
In fact, people who cannot do proofs cannot do mathematics.
I fear that your passion is simply and tragically misplaced.
So you must learn to do logic and proofs.