Write a real world problem of Simplifying Exponent Expressions and solve (also how you did it)

Which of the following graphs could represent a cubic function?

Two numbers have a sum of -19. one number is x. what expression represents the other number?

The party planning committee has to determine the number of tables needed for an upcoming event. if a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.