13x = 2(5x+3) solve for x

Find the solution of this system of equation -7x+y=-20 9x-3y=36

How many solutions does the nonlinear system of equations graphed bellow have?

(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.