Posted by AMY on Friday, November 26, 2010 at 7:57pm.
Media services charges $40 for a phone and 20/mth for its economy plan. It says to find a model that determines the total cost, C(t), of operationg a media Services phone for t months. I think the answer should be in this equation  y = mx+b. Not sure.
Algebra/Equations,functions  MathMate, Friday, November 26, 2010 at 11:34am
So far so good.
What values would you assign to m and b to complete the operation model?
Algebra/Equations,functions  AMY, Friday, November 26, 2010 at 12:47pm
y = 40x+20?
Algebra/Equations,functions  MathMate, Friday, November 26, 2010 at 1:33pm
Correct!
Algebra/Equations,functions  MathMate, Friday, November 26, 2010 at 1:35pm
Watch out, it's $20/month and the phone (one time only) is $40.
so the equation should be:....
Algebra/Equations,functions  AMY, Friday, November 26, 2010 at 5:19pm
not sure but will take a stab at it. y = 20x +40?
Algebra/Equations,functions  AMY, Friday, November 26, 2010 at 6:44pm
Nope that was wrong on my part. I believe the final answer is C(t) = 20t+40
Algebra/Equations,functions  AMY, Friday, November 26, 2010 at 7:55pm
I also need to find the total cost. This is what I have.
C = 20(0) +40. (0,40).
C (5) = 20 (5) + 40.
C (5) = 100 +40 = 140 (5, 140)
So the total cost is 130. IS THIS RIGHT? Thank you!

FOR MATHMATE  MathMate, Friday, November 26, 2010 at 8:52pm
Thank you for the followup. Sorry that I didn't check your responses.
Yes, in a function, we normally assume that
C(x)=ax+b
is equivalent to
C(t)=at+b
because t is a "dummy" variable.
However in your case, t has been stated as the variable, so it is more correct to define function as:
C(t)=20t+40
Hope you understood fully why $20 per month is associated with the variable t.

FOR MATHMATE  AMY, Friday, November 26, 2010 at 9:23pm
Yes. DId you see the total cost?? Was I right with the answer to that one? I think I was right.

FOR MATHMATE  MathMate, Friday, November 26, 2010 at 10:46pm
No, I didn't.
But if total cost for t months,
C(t) = 20t + 40, then
For 0 month:
C(0) = 20(0)+40 = 40
for 4 months:
C(4) = 20(4)+40 = 120
for 5 months:
C(5) = 20(5)+40 = 140
I do not understand how you get 130 (for 5 months)!
The question has not stipulated for how many months the total cost should be calculated.
Answer This Question
Related Questions
 Algebra/Equations,functions  Media services charges $40 for a phone and 20/mth ...
 math  media service charges $30 for a phone and $20 month for its economy plan...
 matt  Media Services charge $30 for a phone and $20/month for its economy plan...
 Math  Media service charges $20 for a phone and $30/month for its economy plan...
 Math  Media service charges $20 for a phone and $30/month for its economy plan...
 algebra  help please im on my final exam for algebra and i need to pass this is...
 mathword problem  Media Services charge $20 for a phone and $30/month for its ...
 Algebra/Word problem  media services charges $20 for a phone and $30/month for ...
 Math 116  1.Write an equation of the line containing the given points and ...
 Math 116  1.Write an equation of the line containing the given points and ...
More Related Questions