Question

a cell phone company has a basic monthly plan of $40 plus $0.45 for any minutes used over 700. Before receiving his statement, John saw he was charged a total of $48.10. Write and solve an equation to determine how many minutes he must have used during the month. write an equation without decimals.

Answer 1

Answer: 718

Step-by-step explanation:

The formula for determining the cost of the cell phone bill (when more than the base number of minutes is used) is

c=p+(m−b)r

Where:

c is the total cost of the bill: $48.10 for this problem.

p is the base price of the plan: $40 for this problem.

m is the number of minutes used: what we are solving for this problem.

b is the base number of minutes allowed: 700 for this problem

r is the rate for additional minutes: 0.45 for this problem

Substituting and solving for m gives:

$48.10 = $40.00 + (m − 700)$0.45

$48.10 − -$40- = $40.00 − -$40- + (m − 700)$0.45 $8.10= 0 + (m−700)$0.45

$8.10 = (m - 700)$0.45

$8.10 = ($0.45 × m) − ($0.45 × 700)

$8.10 = $0.45m − $315.00

$8.10 + -$315.00- = $0.45m − $315.00 + -$315.00-

$323.10 = $0.45m − 0

$323.10 = $0.45m

`(323.10)/(-0.45-)=(0.45m)/(-0.45-)` (Money)

`(323.10)/(0.45)=(0.45m)/(0.45)` (Money): cross out the dollar sign for 323.10 and 0.45 under it... then cross out 0.45m but leave the m, and then cross out 0.45 under it.

`(323.10)/(-0.45-)=m`

718 = m

m = 718

John used 718 total minutes during the month.