What is the rate or change

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?

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?

Do you mind if you guys me with this question i’m on number 8