5. The monthly cost C, in dollars, for calls from the Unites States to Germany on a 1 certain wireless plan is modeled by the function O() = = + 5, where r is the number of minutes used. a) What is the cost if you talk on phone for 40 minutes. b) Suppose that your monthly bill is $22. How many minutes did you use the phone. c) Suppose that you budget $50 per month for calls to Germany. What is the maxi- mum number of minutes that you can talk