Carlos bought a new cell phone. The graph represents the relationship between the number of minutes he uses and the total cost. What is the equation of the line? Total Cost (in dollars) X 0 20 40 60 80 100 120 140 160 180 200 Number of Minutes O y = 5x+0.1 O y = 0.1x+5 O y = 0.5x+5 O y = 5x+5

(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.