I need precalculus help fast!!!

Question

A 19-inch candle is lit and steadily burns until it is burned out. Let b represent the burned length of the candle (in inches) and let r represent the remaining length of the candle (in inches).

A. Write a formula that expresses r in terms of b.

B When 4.5 inches have burned from the candle, the remaining length of the candle is (answer here)  inches. Therefore the point(answer here) should be on the graph of r in terms of b.

Answer 1

A. r = 19 - b

B. r = 19 - 4.5