Question

Xin is going to use a computer at an internet cafe. The cafe charges $0.80 for every minute using a computer on top of an initial charge of $7. Make a table of values and then write an equation for C, commaC, in terms of t, commat, representing the total cost of using a computer for tt minutes at the internet cafe.
Number of Minutes Total Cost to Use Computer
00
11
22
33
Answer
Attempt 1 out of 2

Answer 1

To find the total cost \( C \) of using a computer for \( t \) minutes at the internet cafe, we can calculate the total cost for the different values of \( t \) as given in the problem. The total cost consists of a fixed initial charge plus a charge per minute.

The structure of the cost is:
\[ C = \text{initial charge} + \text{cost per minute} \times t \]

In this case:
- Initial charge = $7
- Cost per minute = $0.80
- Therefore, the equation for total cost \( C \) in terms of time \( t \) in minutes is:
\[ C = 7 + 0.80t \]

Now, let's create a table with the given values of \( t \):

| Number of Minutes (t) | Total Cost (C) |
|-----------------------|--------------------|
| 0 | \( 7 + 0.80(0) = 7 \) = $7.00 |
| 1 | \( 7 + 0.80(1) = 7 + 0.80 = 7.80 \) = $7.80 |
| 2 | \( 7 + 0.80(2) = 7 + 1.60 = 8.60 \) = $8.60 |
| 3 | \( 7 + 0.80(3) = 7 + 2.40 = 9.40 \) = $9.40 |

So the completed table is:

| Number of Minutes (t) | Total Cost (C) |
|-----------------------|-----------------|
| 0 | $7.00 |
| 1 | $7.80 |
| 2 | $8.60 |
| 3 | $9.40 |

Finally, the equation representing the total cost \( C \) in terms of minutes \( t \) is:

\[
C = 7 + 0.80t
\]