During the period 2000-2016, the average costs B (in dollars) for a new boat and the average costs H (in dollars) for a hovercraft can be modeled by the following functions:
B = 30 +140 and H=-1012 +350 + 400
where t is the number of years since 2000
(a) How can the difference of the costs of a hovercraft and the costs of a boat be expressed? (4 points)
(b) About how much was the difference in the year 2010? (2 points)