The number of hours, h, it takes for a block of ice to melt varies inversely as the temperature, t. if it takes 2 hours for a square inch of ice to melt at 70 degrees, find the constant of proportionality

This is an inverse or indirect variation problem that would be set up as y=k/x if you were using y and x.  Since you are using h and t, it would look like this:
h=k/t, where k is the constant of variation. Fill in the formula with the h and the t they give you: 2=k/70. Multiply both sides by 70 to get a constant of variation value of 140.

In all honesty, there really is no “work” per say to show. mainly it’s just using the process of elimination. the question is asking which domain(s) would be the most appropriate for the function c(n). n is the number of observed vehicles so right away, 1, 2, and 3 can be eliminated.why? 1, 2 start in the negatives and therefore it is impossible to observe negative cars. so, #4 would be the best answer to the given problem.