In the equations 6x - 2y = a and 3x - 6y = b, a and b are constants. The two equations have infinitely many solutions. Which of the following are true? (Select all that apply.)

If a=5, then b=10
If a=18, then b= 9
If a=8, then b=4
if a=14, then b=28

(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.