What is the equation of the line that passes through (0, 3) and (7, 0)? a) y= 3/7x - 3 b) y= 3/7x + 3 c) y= -3/7x + 3 d) y= -3/7x-3

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?