Round to the nearest hundred 5,503,569

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?

Can someone tell me if this is perpendicular? !

State one method by which you can recognize a perfect square trinomial.