Which relation is a function?

a. x −2 0 0 2 4
y 4 3 4 4 6

b. x 3 5 7 10 14
y 9 6 9 2 3

c. x −3 2 2 4 6
y 2 1 8 5 3

d. x −6 −1 1 1 6
y 0 6 2 −3 4

Asurvey of 45 teens found that they spent an average of 25.6 hours per week in front of a screen (television, computer, tablet, phone, based on the survey’s sample mean, which value could be the population mean? 2.3 hours 27.4 hours 75.3 hours 41.5 hours

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

21 type the correct answer in the box. use numerals instead of words. if necessary, use / for the fraction bar. the solution set of n2 - 14n = -45 is { (separate the solutions with a comma)