SOLUTION: Plan A cost $20 per month plus $0.15 for each minute used. Plan B cost $15 per month plus $0.20 for each minute used. What equation can be written to represent the cost of each pla

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Plan A cost $20 per month plus $0.15 for each minute used. Plan B cost $15 per month plus $0.20 for each minute used. What equation can be written to represent the cost of each pla      Log On


   

Question 732985: Plan A cost $20 per month plus $0.15 for each minute used. Plan B cost $15 per month plus $0.20 for each minute used. What equation can be written to represent the cost of each plan? After how many minutes is the cost the same?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Plan A cost $20 per month plus $0.15 for each minute used. Plan B cost $15 per month plus $0.20 for each minute used. What equation can be written to represent the cost of each plan? After how many minutes is the cost the same?
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A(x) = 20 + 0.15x
B(x) = 15 + 0.20x
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Graphing:
y = 20 + 0.15x
Let x = 0, then y = 20
Let x = 100, then y = 20+15 = 35
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Plot the 2 points and draw a line thru them.
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y = 15 + 0.20x
Let x = 0, then y = 15
Let x = 100, then y = 15+20 = 35
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Plot the 2 points and draw a line thru them.
graph%28400%2C400%2C-25%2C150%2C-25%2C75%2C20%2B0.15x%2C15%2B0.20x%29
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Equation:
20 + 0.15x = 15+0.20x
5 = 0.05x
x = 100 minutes
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Cheers,
Stan H.
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