Which of the following equations have no solutions?

What is the number 321,000,000 in scientific notation? also what is the number? ?

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?

How much orange juice do you need to make 2 servings of lemony orange slush?