Question

Which of these operations are commutative for integers?

• A. Addition
• B. Subtraction
• C. Multiplication
• D. Division

Answer 1

Answer: (A), (C)

The correct options are
A Addition
C Multiplication

Addition and multiplication are commutative for integers.

If $a$ and $b$ are integers, then
$a+b=b+a$
Example : 1 + 2 = 2 + 1 = 3

$a\times b=b\times a$
Example : 1 $\times$ 2 = 2 $\times$ 1 = 2

On the other hand, subtraction and division are not commutative for integers.

If $a$ and $b$ are integers, then
$a-b\ne b-a$
Example : (1 - 2) = -1 $\ne$ (2 - 1) = 1

$a÷b\ne b÷a$
Example : (1 $÷$ 2) = $\frac{1}{2}$ $\ne$ (2 $÷$ 1) = 2