Answer:
The answer is below
Step-by-step explanation:
The equation for a linear function is given as:
y = mx + b
where m is the slope of the function (that is the rate of change), b is the initial value of y when x is 0.
Given that the function where x represent the number of years since 1960 and y is the cost in dollar as:

a) In the year 1960, that is x = 0, the cost of a gallon of gas is given as:

b) From the function
, we can see that the rate of change is 2.14/55. Therefore, the cost increase each year by 4 cents per year.