Question 365373: i need to come up with a word problem involving a cell phone plan using system of equations. can you help mee?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! I assume they want equations that compare the cost of one cell phone company
with another, for a specific number of minutes used per month.
:
Co. A: $40 a month, with 500 free minutes, 10 cents a minute after that
The equation for this; let m = no. of minutes used:
C = .10(m - 500) + 40
:
Co. B: $25 a month, all minutes cost you 5 cents
C = .05m + 25
:
Say you talk about 20 min a day, which plan would be the best deal?
30 * 20 = 600 min per month
Plan A:
C = .10(600-500) + 40
C = .10(100) + 40
C = 10 + 40
C = $50
:
Plan B:
C = .05(600) + 25
C = 30 + 25
C = $55
:
So with this scenario, Plan A is best for you
:
A good question would be, how many minutes would cost the same with each plan.
Plan A = Plan B; solve for m
.10(m-500) + 40 = .05m + 25
.10m - 50 + 40 = .05m + 25
.10m - 10 = .05m + 25
.10m - .05m = 25 + 10
.05m = 35
m = 
m = 700 minutes
:
Substitute 700 for m in each equation, will see they both cost $60
Greater than 700 min, Plan B will be a better deal for you
Confirm this by seeing the cost of 800 min for each plan.
:
:
Does this make sense to you? A good thing to know, something that applies
to decisions you will make in real life, Do you have any questions about this?
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