Legs
Yes, the difference between two even numbers is always an even number.
No, the sum of a prime number and a composite number is not always even.
It CAN'T be even, since the number 2 is not a factor of the odd number. "Even" means that a number is a multiple of 2.
When you multiply an odd number by an even number, you are essentially adding an even number of odd numbers together. Since adding an even number of odd numbers will always result in an even number, the product will be even.
An odd number squared would always equal an odd number and an even number squared would always equal an even