Question

ivan purchased a prepaid phone card for $30.50. calls cost 6 cents a minute using this card. the credit, c (in dollars), left on the card after it is used for x minutes of calls is given by the following.
c = 30.50 - 0.06x
how much credit is left on the card after ivan uses it for 50 minutes of calls?

dollars

Explanation:

Step1: Identify the value of x

We know that Ivan uses the card for 50 minutes, so \( x = 50 \).

Step2: Substitute x into the formula

The formula for the credit left is \( C = 30.50 - 0.06x \). Substitute \( x = 50 \) into the formula:
\( C = 30.50 - 0.06\times50 \)

Step3: Calculate the multiplication

First, calculate \( 0.06\times50 = 3 \).

Step4: Calculate the subtraction

Then, subtract this from the initial credit: \( C = 30.50 - 3 = 27.50 \).

Answer:

27.50