Question 193959: I need some advice. Could someone please tell me if my answer is right? I don't need to show the problem, just the answer. Media services charges $20 for a phone plus $30mth for it's cheapest plan. The equation c=30t+20 describes the total cost,c, of operating a Media Services phone for tmths. What is the total cost for 8 mths. of service? I got $260, is that right? Then the second part is what I'm not sure of. If a customer only has $90 available, how many mths of services can he or she recieve? I divided by 90 without the $20 it's 2.6 and then I added the $20 it's 2.8. Is this right and which way did they mean it? Than-x I appreciate it. Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website! Your answer to the first part is correct!
For the second part, you need to set the total cost, c = $90 then solve for t, thus... Substitute c = 90 Subtract 20 from both sides. Now divide both sides by 30. so...
For $90 the customer can get 2 1/3 months of service.
Check: Substitute t = 2 1/3
(