Question

Drake is considering buying one of the four popular e-readers where the e-reader's premium services is a monthly charge. The functions LaTeX: A_1\left(t\right)=\:5t+350,\:\:\:A_2\left(t\right)=10t+250,\:\:\:\:\:A_3\left(t\right)=499,\:and\:\:\:\:\:\:A_4\left(t\right)=15t+179A 1 ( t ) = 5 t + 350 , A 2 ( t ) = 10 t + 250 , A 3 ( t ) = 499 , a n d A 4 ( t ) = 15 t + 179 model the total amount of money A, in dollars, that Drake spends after buying the e-reader and subscribing to t months of the e-reader's premium services. Which e-reader has the greatest monthly subscription cost?

Answer 1

`A_4`

Explanation:

The cost of the e-readers and the subscription of their services are

`A_1(t)=5t+350`

`A_2(t)=10t+250`

`A_3(t)=499`

`A_4(t)=15t+179`

The functions are of the form

`A(t)=mt+c`

Where
`m` is the monthly subscription cost and
`c` is the cost of the e-reader.

So, 15 dollars is the highest subscription cost which is of the 4th e-reader.

Hence
`A_4` has the highest subscription cost.