Question

Make a conjecture about the cube of a number. Then, make a counterexample to disprove your
conjecture about the cube of a number.
-x^3 , 0^3 , 1^3 , 2^3 , y^3 ...

Answer 1

Hmm this seems really simple....
Just think of something extra stupid and easy for your conjecture.
Here is mine: "The cube of any integer is divisible by 3."
Then provide a number cubed which is not divisible by 3 to show that the conjecture is false.

I dunno, just an idea :P