Answer: Commutative property of multiplication.
Explanation:

In algebra, the commutative property of multiplication tells that two numbers can be multiplied in either order.
ab=ba, where a and b be any two real numbers
It doesn't matter that which number should be written first or next, because if you change the order of product, the answer remains the same. The answer doesn't change with the change of order.
For example :- 3×5=5×3=15