Brock is a plumber. he charges a flat rate of $40 to visit a house to inspect its plumbing. he charges an additional $20 for every hour he spends inspecting or making repairs which graph below correctly shows the price of using brocks plumbing service vs time?
a) graph w
b) graph x
c) graph y
d) graph z

Your vet has placed your pet on a diet. the diet is to contain at least 12 mg of fat and at least 14 mg of protein per serving. these requirements are to be obtained from two food sources. source a contains 2 mg of fat and 2 mg of protein per serving. source b contains 1 mg of fat and 3 mg of protein per serving. if source a sells for $1.28 per serving and source b sells for $1.12 per serving, how many servings of each type should be purchased to satisfy the requirements at minimal cost?