For which to pairs of function is (f•g) (x) =x

and

Step-by-step explanation:

To prove that we have to demonstrate

This proof is about a composition of functions, where we have to enter one function inside another, in this case, goes inside . So if results in , then will be proved.

As you can see, the composition is to replace for the variable of .

Solving the expression:

After replacing and applying the composition, we have as a result. Therefore, we can say that the pair of functions of option B is the answer, because they satisfy the expression given.

45

step-by-step explanation: