Question

A student wants to buy a new cell phone. Teen-Mobile charges $15 a month plus $10 for every one gigabyte of data used. Bruh-rizon charges $30 a month plus $7 for every one gigabyte of data used.

Use the information provided to identify the growth (or unit rate of change) and starting value for:

Answer 1

Let's define T(x) as the cost with the company Teen-Mobile, where x is the number of gigabytes used.

We have a constant fee of $15 plus extra $10 for each gigabyte used, then:

T(x) = $15 + $10*x

Let's define B(x), same as above, but for the company Bruh-rizon.

Here we have a constant of $30 plus $7 for each gigabyte used.

B(x) = $30 + $7*x

Where in each equation, the growth rate is the coefficient multiplicating the x (also called the slope) , and the other factor is the starting value (also called the y-intercept).

Now knowing the number of gigas that you use in a month, can decide which option is best for you.