SOLUTION: 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 f

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(57219) (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?
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Make it a piecewise-defined function:
Cost = $22.00 .........., 0<= x <=150
.....= $22.00 + 0.75x .., x > 150
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Cheers,
Stan H.