x and y are positive integers. If xy + x is odd, then which of the following must be even?
.	Choose the correct choice from the following answers
A) x	B) y	C) x + y	D) xy − x	E) x^2 − y
Two possibilities:   (1) even + odd = odd   (2) odd + even= odd   In this case, x can not be even as it will make xy also even .   Therefore, (1) possibility present =&gt; y must be even.   Answer: y
<result>B</result>
x and y are positive integers. If xy + x is odd, then which of the following must be even?
.