How do you find out whether somethings a function or not?

Aline passes through 3,7 and 6,9 what equation represents the line

Suppose that in 2008 , 840,800 citizens died of a certain disease assuming the population of teh country is 399 miliion, what is the mortality rate in units of deaths per 100,000 people?

Maren is buying carpet for her rectangular living room. the room is 4.8 yards wide and 5.2 yards long. how much carpet does she need to buy? enter your answer as a decimal in the box. yd2