Which of the following expressions represents a function?

a.{(1,,-,,-3)}
b. y^2=16-x^2
c.2x^2+y^2=5
d. x=7

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

Is of - 4x + 2? a. 3 b. 4 c. 6 d. 5

Mariano delivers newspaper. he always puts 3/4 of his weekly earnings in his savings account and then divides the rest equally into 3 piggy banks for spending at the snack shop, the arcade and the subway