Answer:
20 + 0.05m
Explanation:
The phone company charges a standard fee as well as a fee for every minute of long distance.
When no minutes are used, the cost is $20. This means that the standard fee is $20.
For 10 minutes, the cost is $20.50. The standard fee is $20. This means that for ten minutes, $0.50 is charged. For one minute, the charge is $0.05,
$20.50 - $20 = $0.50
$0.50/10 = $0.05
Dan's monthly cost is the standard fee plus the charge per minute.
20 + 0.05m