SOLUTION: Mary purchased a prepaid phone card for $20 . Long distance calls cost 18 cents a minute using this card. Mary used her card only once to make a long distance call. If the r

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Mary purchased a prepaid phone card for $20 . Long distance calls cost 18 cents a minute using this card. Mary used her card only once to make a long distance call. If the r      Log On