| 
 
 
| Question 527252:  Granny Day has signed up for a new cell phone plan! She hs decided to get with the current world and learn to text! For the plan she chose, her monthly cost is $ 22.00 plus $ .75 for each text messages over 150 text messages.
 What equation could be used to determine the total cost of her monthly cell phone bill, y, if she sends x text messages?
 What I have done...
 Y= .75(x-150)+22  but my teacher says it is wrong because if she uses less than 150 text messages they would not pay her.  I have also thought of using ((x-150)>150).75)+22 meaning if it is greater than do the next step but if not you just have it as $22. Or f(x<150)=22  f(x>150)= .75(x-150)+22
 I would be greatly honored if you would help me.
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! Granny Day has signed up for a new cell phone plan! She hs decided to get with the current world and learn to text! For the plan she chose, her monthly cost is $ 22.00 plus $ .75 for each text messages over 150 text messages. What equation could be used to determine the total cost of her monthly cell phone bill, y, if she sends x text messages?
 ----
 Make it a piecewise-defined function:
 Cost = $22.00 .........., 0<= x <=150
 .....= $22.00 + 0.75x .., x > 150
 ======================
 Cheers,
 Stan H.
 | 
  
 | 
 |