Which best describes the rate of change?

(c) the diagram shows the first three shapes of a matchsticks arrangement.first shape = 3second shape = 5third shape = 7given m represents the number of matchstick used to arrange the n'th shape.(i) write a formula to represent the relation between m and n. express m as the subjectof the formula.(ii) 19 matchsticks are used to make the p'th shape. find the value of p.

We have 339 ounces of jam to be divided up equally for 12 people how muny ounces will each person get

How is this equation completed? i cannot find any examples in the book.