Question

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

a. 2x2 - 4x + 2 will be a polynomial
b. 2x2 - 4x + 2 may or may not be a polynomial
c. 2x2 - 12x - 10 will be a polynomial
d. 2x2 - 12x - 10 may or may not be a polynomial

Answer 1

The answer is a. 2x2 - 4x + 2 will be a polynomial

Explanation:

Answer 2

The answer is a. 2x2 - 4x + 2 will be a polynomial

(4x + 6) + (2x² - 8x - 4)
= 4x + 6 + 2x² - 8x - 4
= 2x² + (4x - 8x) + (6 - 4)
= 2x² - 4x + 2

And it is polynomial (it has more than 1 term)