Question

Which of the following shows that polynomials are closed under addition when two polynomials 4x2 − 8x − 7 and −5x + 16 are added?

4x2 − 13x + 9 may or may not be a polynomial.

4x2 + 13x − 23 may or may not be a polynomial.

4x2 − 13x + 9 will be a polynomial.

4x2 + 13x − 23 will be a polynomial.

Answer 1

Im pretty sure the answer is C because the polynomial discriminate is 100 hope this helps

Answer 2

The correct option is 3.

Explanation:

The given polynomials are

`4x^2-8x-7`

`-5x+16`

We need to add these polynomials.

`4x^2-8x-7-5x+16`

Combine like terms.

`4x^2+(-8x-5x)+(-7+16)`

`4x^2+(-13x)+(9)`

`4x^2-13x+9`

The sum of two polynomials is always a polynomial.

The expression
`4x^2-13x+9` is a polynomial.

Therefore the correct option is 3.