Respuesta :
Answer:
1) For 450 minutes of calling the two plans cost the same.
2) The cost when the two plans cost the same is $56.5.
Step-by-step explanation:
The cost of both plans can be modeled by linear functions.
Plan A:
$25 plus an additional $0.07 for each minute of calls.
So, for t minutes of calls, the cost is:
[tex]A(t) = 25 + 0.07t[/tex]
Plan B:
$16 plus an additional $0.09 for each minute of calls.
So, for t minutes of calls, the cost is:
[tex]B(t) = 16 + 0.09t[/tex]
Q1: For what amount of calling do the two plans cost the same?
This is t for which:
[tex]A(t) = B(t)[/tex]
[tex]25 + 0.07t = 16 + 0.09t[/tex]
[tex]0.02t = 9[/tex]
[tex]t = \frac{9}{0.02}[/tex]
[tex]t = 450[/tex]
For 450 minutes of calling the two plans cost the same.
Q2: What is the cost when the two plans cost the same?
This is A(450) or B(450), since they are the same.
[tex]B(450) = 16 + 0.09*450 = 56.5[/tex]
The cost when the two plans cost the same is $56.5.
