The first thing we are going to do in this case is define variables:
F = the amount of flour in the bin
c = signature cakes
We write the equation that best fits the problem which will be given by:
F = -1.5c + 30
Answer:
An equation that represents the amount of flour in the bin, F, after he bakes c signature cakes is:
F = -1.5c + 30
See attached graph.