15. (192) In the equation z = x2 + y?, find the value of = when x - -2 and y = 3. a) 23 b) 19 c) 13 d) 9 e) None of the above 16. (192) In the equation V = =$2h, find the value of I/ when s - 6 and / = 10. 2) 265 b) 120 C) 69 d) 14 e) None of the above 17. (Lov) Factor the expression: x? - Axy + ty? a) (x + 4y) (x - y) b) (2 - Zy) (2x - 2y) c) (x - y) (2x - 2y) d) (x - Zy) (x - 2y) e) (x - 4y) (x - 2y) 18. (1100) Factor the expression. 2587 - 16y a) (5x - 4y) (51 - 4y) b) (5x + 4y) (5x - 4y) c) (25x + 16y) (x - y) d) (x + y)(25x - 16y) e) (5x + 4y) (5x + 4y) 19. (LIMS) Which of the following represents the equation M - er + a after it has been solved for c? a) = b ) c = M = a C) c = M- a d) c = Mx + a e) c = Ma - x