Phone Plan A advertises a rate of $0.25 per minute, while phone Plan B advertises a rate of $0.17 per minute for the first 100 minutes and $0.32 for each additional minute.

Identify which plan has a variable rate of change and explain why the rate is variable.

Identify the cost for phone Plan A and for phone Plan B when 100 minutes are used. Show all your work.

Compare Plan A and Plan B and describe when phone Plan A is a better deal than Plan B. Show work to support your answer.​