The expression xy+x is odd when the x and y are integers.

The expression xy+x is odd when the x and y are integers. Which of the following expressions must be even?

Quiz

Answer/Solution

y

Steps/Work

xy+x is odd
x and y are integers
If x were even xy+x would be even despite any value of y.
y can't be odd, so y must be even.
Ans : B