How do I write an integer that can be represented by x and the next integer can then be represented as (x + 1) and still show that the sum of any two consecutive integers are always odd

First integer x

the next integer x+1

The sum:

x+x+1 = 2x + 1

product of multiply any number by 2 is always an even number

so 2x is an even number and 2x+1 is the next number past number 2x.

It means the number 2x+1 is odd