Use the graph of the function to find the domain and range of f.

The domain is the x-values u insert to get corresponding y-values. In other words, the domain is the boundaries for which u can enter x valies. In this graph, we can see that the function continues infinitely upwards, not vertical shifting a bit to the sides. This means that the domain is all x belonging to the set R, since for any x value, we will get a corresponding point on the graph. For the range, it is simply the range of the y-values. From the graph, teh range is -4

If i think this is what your asking, he should look at the grams or pounds/ounces and compare the to their cost then max can identify which one is proportional and which is not ( i think xd)