Question

Use a direct proof to show that the sum of two even integers is even. Use the contrapositive (indirect proof).

Answer 1

you want a direct proof ?

Answer 2

Let a,b be two even integers. then a = 2k , and b = 2m for some integers k,m.
a + b = (2k + 2m) = 2 ( k+m)

Now a+b is even since a + b = 2 * p , where p = k + m

Answer 3

contrapositive proof please