If a and b are odd numbers, which of the following expressions is even?

Given data

• a and b are odd integers.

Concept / Approach

• Parity rules: odd ± odd = even; odd × odd = odd; odd squared remains odd.

Step-by-step reasoning

ab: odd × odd = odd \u2192 odda^2 b: odd^2 × odd = odd × odd = oddab^2: odd × odd^2 = odd × odd = odda + b: odd + odd = even

Common pitfalls

• Assuming any power makes a number even; parity of odd numbers is invariant under powers.

Final Answer

a + b