# 1. Use a direct proof to show that the sum of two odd integers is even. 2. Use a direct proof to show that the sum of two even integers is even. 3. Show that the square of an even number is an even number using a direct proof. 4. Show that the additive inverse, or negative, of an even number is an even number using a direct proof. 5. Prove that if m+n and n+p are even integers, where m,n, and p are integers, then m+p is even. What kind of proof did you use? 6. Use a direct proof to show that the product of two odd numbers is odd. 7. Use a direct proof to show that every odd integer is the difference of two squares. 8. Prove that if n is a perfect square, then n+2 is not a perfect square.

X