What is the value of -2x+3yz if x=3, y=6, and z=

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?

Math it's appreciated. (picture provided)

8litres of paint can cover 129.6 m². how much paint is required to paint an area of 243m²?