Dudley is biking. He wants to cover 40 miles. If he travels 30 miles every 2 hours, what is the equation of a line that models y, the number of miles he has left to travel, after biking x hours?
 A. y = -15x – 40
 B. y = -30x + 40
 C. y = -15x + 40
 D. y = 30x – 40
 I need answers as soon as possible .
 Thanks