Which of the following equations demonstrate that the set of polynomials is not closed under the certain operations? a. division: (x^2+2x) / (x+1) = x+ x/x+1 b. multip.: (3x^4++x^3)= -6x^6+ x^7+x^6 c. addition: (3x^4+x^3)+(-2x^4+x^3)= x^4 + 2x^3 d. multip.: (x^2+2x)(x+1)= x^3 +3x^2+2x

The correct answer is A) Division.

Explanation:
When we divide these two polynomials, we get an answer that is not a polynomial. This is due to the rational portion of the answer, x/(x+1).

We know from our definitions of polynomials and monomials that if there is a variable with a negative exponent, that means that we do not have a monomial and therefore not a polynomial. Having x+1 in the denominator means it would have a negative exponent, and is therefore not a polynomial.

Since we divided two polynomials and had a result that was not a polynomial, this means that the set of polynomials is not closed under division.

B.the point lies directly on the regression