Question 936794
Cell Company offers a single line plan for $50.
 they want to offer a family plan for 2 lines or more under the same plan. doing so you will decrease the charges per line by $5 each, (the costs per line would decrease for all lines, not just for the lines beyond the first 2.
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I am assuming that each line is $5 less than the previous line
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Let x = no. of lines
1. What is the costs per line?
50 - 5(x-1)
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2. If you have five lines under the same family plan what will the total costs be.
x(50 - 5(x-1))
x=5
5(50 - 5(5-1)) = 5(50-5(4)) = 5(50-20) = 5(30) = $150 for five lines
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3. if you have 8 lines under the same family plan what will be the total costs.
x=8
8(50 - 5(8-1)) = 8(50 - 35) = 8(15) = $120 for eight lines
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4. what would be the factored form and the general form for the total costs of the family plan as a function of the number of lines beyond 2
f(x) = x(50 - 5(x-1))
f(x) = x(50 - 5x + 5)
f(x = 50x - 5x^2 + 5x
f(x) = -5x^2 + 55x
can be factored to
f(x) = -5x(x - 11)
This is interesting in that if you get 11 lines, you pay 0!
If you get 12 lines they pay you $60!
Maybe I missed something here
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You are not a dumb parent, you are a smart parent, the dumb parent does not try to personally help his child. CK