Salma purchased a prepaid phone card for 30. Long distance calls cost 9 cents a minute using this ca

Salma purchased a prepaid phone card for 30. Long distance calls cost 9 cents a minute using this card. Salma used her card only once to make a long distance call. If the remaining credit on her card is 28.38, how many minutes did her call last?

Set up the equation where m is the number of minutes used:
0.09m = 30 - 28.38
0.09m = 1.62

Divide each side by 0.09
m = 18