10 right or am I really confused.
I think you're a little tired
0.1 is [tex]\frac{1}{10}[/tex]
And this multiplied by 10 gives:
[tex]\frac{1}{10}\times 10 = 1[/tex]
Not 10!
so one is my answer to how many minutes a month I need?
Nuh huh. 100 should be your answer.
100 divided by 10 gives 10.
See how it works:
[tex]0.1(100) = 10[/tex]
And from our two initial equations:
[tex]y_A = 0.22x + 25 = 0.22(100) + 25 = 47[/tex]
[tex]y_B = 0.12x + 35 = 0.12(100) + 35 = 47[/tex]
So anything longer than or equal to 100 minutes is your answer.
Here is the graph of the two lines:
The blue line represents the total cost that company A charges and the purple line represents the total cost that company B charges. You see that for the most part, the line for company B is above that of company A, meaning that for those minutes, company B is more expensive. The point where they meet is where they charge the same fee and as soon as the purple line goes blow the blue line, company B is charging less expensive fees.
Last edited by Unknown008; 12-01-2011 at 03:14 AM.
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