Brittany saved $30 each much in a jar of 3 1/2 years. she spent 50% of the savings on a flat screen television. how much money did brittany have left in the jar?

Players on the school soccer team are selling candles to raise money for an upcoming trip. each player has 24 candles to sell. if a player sells 4 candles a profit of$30 is made. if he sells 12 candles a profit of $70 is made. determine an equation to model his situation?