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

Don't know how to find x given these segment lengths

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?