Question

The charges for an international call made using the calling card for two phone companies are shown in the table. a. What is the length of a phone call that would cost the same no matter which company is used? b. Analyze Relationships When is it better to use the card from Company B?

Phone Company Charges
Company A 35¢ plus 3¢ per minute
Company B 45¢ plus 2¢ per minute

Answer 1

3 is 11plus to sec

2 is 22 plus 3 sec

Answer 2

Part A:

Let the number of minutes for both companies to have the same cost be = x

For company A :

`35+3x`

For company B :

`45+2x`

To get the length of call same, we will equal both the equations.

`35+3x=45+2x`

Solving for x;

`3x-2x=45-35`

x = 10 minutes

Part B:

After 10 minutes, it will be better to use company B as after 10 minutes, company A will be costly.

When x = 12

A :
`35+3x`

`35+3(12)` = 71 cents

B:
`45+2x`

`45+2(12)` = 69 cents

When x = 13

A :
`35+3x`

`35+3(13)` = 74 cents

B:
`45+2x`

`45+2(13)` = 71 cents

With each increasing minute, company A will become costly as compared to B.