English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

Customers of a phone company can choose between two service plans for long distance calls. The first plan has a $20 one-time activation fee and charges 12 cents a minute. The second plan has no activation fee and charges 16 cents a minute. After how many minutes of long distance calls will the costs of the two plans be equal?

2006-11-27 11:50:04 · 5 answers · asked by Anonymous in Science & Mathematics Mathematics

5 answers

f(m) = 2000 + 12m
g(m) = 16m

Set these equivalent:
16m = 2000 + 12m
4m = 2000
m = 500

2006-11-27 11:56:13 · answer #1 · answered by Puzzling 7 · 0 0

Let x = the number of minutes.

Plan A:
0.12x + 20

Plan B:
0.16x

Set the two plans to equal:
0.16x = 0.12x + 20 --- Subtract 0.12x from each side...
0.04x = 20 --- Divide both sides by 0.04...
x = 500

Answer: At 500 minutes, the two plans are equal.

Check:
0.16(500) = 0.12(500) + 20
80 = 60 + 20
80 = 80 --- This checks out!

2006-11-27 19:57:00 · answer #2 · answered by Anonymous · 0 0

set up a system of equations

m=the # of minutes
x=the first plan
y=the second plan

x=12m+20
y=16m

set them equal to find the answer

12m+20=16m
then solve the equation for the answer

2006-11-27 19:53:19 · answer #3 · answered by Ambino 4 · 0 0

500 minutes

2006-11-27 19:54:00 · answer #4 · answered by ramshi 4 · 0 0

y=.12x+20
y= .16x
.16x= .12x+20
.04x=20
x=500

500 minutes

2006-11-27 19:54:44 · answer #5 · answered by      7 · 0 0

fedest.com, questions and answers