Which operation shows that polynomials are a closed system under addition?(1 point)

Answer 1

The operation that shows that polynomials are a closed system under addition is "addition itself".

Answer 2

Which operation shows that polynomials are a closed system under addition?(1 point)
Responses

(2x2+6x+1)+(3x2+3x+9)=(2x2+3x+1)+(3x2+6x+9)
left parenthesis 2 x squared plus 6 x plus 1 right parenthesis plus left parenthesis 3 x squared plus 3 x plus 9 right parenthesis equals left parenthesis 2 x squared plus 3 x plus 1 right parenthesis plus left parenthesis 3 x squared plus 6 x plus 9 right parenthesis

(2x2+6x+1)+(3x2+3x+9)=5x2+9x+10
left parenthesis 2 x squared plus 6 x plus 1 right parenthesis plus left parenthesis 3 x squared plus 3 x plus 9 right parenthesis equals 5 x squared plus 9 x plus 10

(2x2+6x+1)+(3x2+3x+9)=(2x2+3x2)+(6x+3x)+(1+9)
left parenthesis 2 x squared plus 6 x plus 1 right parenthesis plus left parenthesis 3 x squared plus 3 x plus 9 right parenthesis equals left parenthesis 2 x squared plus 3 x squared right parenthesis plus left parenthesis 6 x plus 3 x right parenthesis plus left parenthesis 1 plus 9 right parenthesis

(2x2+6x+1)+(3x2+3x+9)=−x2+3x−8

Answer 3

The correct response is:

(2x^2+6x+1)+(3x^2+3x+9)=(2x^2+3x^2)+(6x+3x)+(1+9)

This shows that polynomials are closed under addition because when two polynomials are added, the resulting polynomial is still a polynomial.