Question

Your cell phone provider charges a monthly fee of $19.50 for 200 minutes. You are also charged $.25 per minute for each minute over 200 minutes. Last month, your bill was $29.50. a. Let m represent the total number of minutes you used last month. Use the verbal model below to write an equation.

Answer 1

T = $19.50 + $0.25(m - 200)

Explanation:

Using the information provided we can create the following equation. This equation subtracts 200 from the total number of minutes and multiplies this by the cost per minute. Then it adds the fixed cost for the initial 200 minutes to get the total of the bill (T).

T = $19.50 + $0.25(m - 200)

Now that we have the equation we can plug-in you total for last month's bill and solve for m to calculate how many minutes you used last month.

$29.50 = $19.50 + $0.25(m - 200) ... distribute 0.25

$29.50 = $19.50 + $0.25m - 50 ... combine like terms

$29.50 = $0.25m - $30.5 ... add 30.5 on both sides

$60 = $0.25m ... divide both sides by 0.25

240 = m

Finally, we can see that you used a total of 240 minutes last month.