Answer:
Multiplication identity
Step-by-step explanation:
We are given that
We have to find which property of real number is used in given expression.
Multiplication identity: It is defined as the number by which multiply any number and get itself.
Then, 1 is multiplication identity.
When we are multiplying 5 with 1 then we get 5.
Therefore, 1 is multiplication identity.
Hence, multiplication property of real numbers is used in given expression.