Please help answering this

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?

Which of the following is the best first step in solving the equation below? 4+2㏒³x=17

Factor and solve to find roots x squared -x - 90 =0