Question

Which of the following shows that polynomials are closed under addition when two polynomials 4x + 6 and 2x2 − 8x − 4 are added?

2x2 − 4x + 2 will be a polynomial
2x2 − 4x + 2 may or may not be a polynomial
2x2 − 12x − 10 will be a polynomial
2x2 − 12x − 10 may or may not be a polynomial

I just don't get this question at all. What does it mean by 'closed under addition'

@welshfella @sammixboo @kidrah69

Answer 1

sorry

2x2 = 2x^2

Answer 2

Well if the polynomials were added, it would end up as a polynomial as well so it has to be A or C, right? then I add the polynomials together and get my final answer right

Answer 3

(4x + 6) + (2x^2 − 8x − 4)

4x + 6 + 2x^2 − 8x − 4

2x^2 - 4 + 2

So that makes it A or B, so I choose A, because of what I said above

Answer 4

That is what I think, Kayla.

Answer 5

hmm ok