What is the base plan for the set if stacked cubes

What is the y-intercept of the line given by the equation

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 expression is equivalent to 3^3 + 2^2?