Assume food prices have risen about 4% per year for the last five years. a. If a gallon of milk cost $2 five years ago, what does it cost today? b. If a gallon of milk cost $x five years ago, write an expression for its cost today. c. If a gallon of milk costs $3.50 now, what did it cost five years ago? Write and solve an equation to answer the question. Let x = cost of a gallon of milk five years ago d. If milk prices increase 4% per year for five years, what is the overall percent increase?