X - number of customers

There can't be a fraction of the number of people, so there must be some mistake in the question.
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Answer: 3
Step-by-step explanation:
Set them equal because they are the same so 15x+5=16x+2 so x+2=5 so x=3
Answer:
For
, the group is CLOSED as it a polynomial.
Step-by-step explanation:
Here, the given polynomials are:

Now, a group G is said to be <u>CLOSED UNDER SUBTRACTION</u> if,
a and b are he elements of G ⇒ (a-b) is ALSO AN ELEMENT of G
Now, here:

or, 
Also, R(x) is a POLYNOMIAL.
So, R(x) is an Element of group G.
So, the set G of polynomials.
Hence, for the polynomial
, it will be a polynomial the group is CLOSED.