Which of the following options correctly describes if the following polynomial forms a closed system under multiplication?

−3(5x+4y)=−15/x−12y


Option #1: Yes, because the result of multiplying the polynomials is also a polynomial.

Option #2: No, because the exponent of x is not a positive integer.

Option #3: No, because multiplying the polynomials resulted in subtraction.

(1 point)
Option #

1 answer

To determine whether the given expression forms a closed system under multiplication, we first need to analyze the components provided.

The expression: \[ -3(5x + 4y) = -\frac{15}{x} - 12y \] suggests that the left side of the equation is a polynomial while the right side contains a term \(-\frac{15}{x}\), which is not a polynomial, since polynomials cannot have negative exponents (a term like \(x^{-1}\) does not satisfy the criteria for being a polynomial).

Let's evaluate the options:

  1. Option #1: Yes, because the result of multiplying the polynomials is also a polynomial.
    This option is incorrect; the right-hand side includes a term that is not a polynomial.

  2. Option #2: No, because the exponent of x is not a positive integer.
    This option is correct; the term \(-\frac{15}{x}\) implies \(x^{-1}\), which does not meet the polynomial definition.

  3. Option #3: No, because multiplying the polynomials resulted in subtraction.
    This option is misleading; the operation does not affect whether it's a polynomial.

Based on the evaluation, the correct answer is Option #2. The system is not closed under multiplication because the result involves a term (\(-\frac{15}{x}\)) that is not a polynomial. Therefore, the final answer is:

Option #2: No, because the exponent of x is not a positive integer.