Please help me with this

Use set builder notation to represent the following set: { -3, -2, -1, 0}

(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.

Which of the following is best modeled using a linear equation y=ax+b, where a is less than 0?