Find the value of k so that (-1,5) lies on kx - 4y -k=0

The graph shows the distance kerri drives on a trip. what is kerri's speed . a. 25 b.75 c.60 d.50

I’m stuck on this equation, anyone got the answer?

The boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a) e = 2b - 212 b) b = 2e - 212 c) e = -2b + 212 d) b = -2e + 212