Asquare garden is 12 feet long on each side janet needs to put a post at each corner. she needs a post every 3 feet on each side

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?