please answer this multi part question

A certain gas reserve held about 19 billion cubic feet of the gas in 2010 and is being depleted by about 1.1 billion cubic feet each year, () Give a linear equation for the remaining gas reserven, R. In terms of t, the number of years since 2030. (Lot R bu menured in billions of cubic feet) RD- (b) in 2015, what will the gas reserves be? (Round your answer to one decimal place) billion ft (c) If the rate of depletion doesn't change, in what year will the gas reserve be depleted? (Round your answer down to the nearest year)