Oxford Mathematics for the New Century 2A 5 Linear Equations in Two Unknowns Consolidation Exercise 5D Level 1 Solve the following simultaneous equations by the method of elimination. [Nos. 116] 1. x y 8 x y 4 2. 6 x 11 y 3 x 16 y 3. x 3 y 7 x y 5 4. 3 x 2 y 3 3 x 2 y 9 5. 4 x 5 y 21 4 x 3 y 13 6. 3 x 5 4 y 5 x 13 4 y 7. 5c d 7 3c d 1 8. h 10k 7 h 4k 25 9. 7 x 3 y 15 5 x 3 y 27 x 3 y 14 10. 3 y x 28 4 y 3 x 15 11. 3 x 4 y 9 3x 5 y 4 12. 3x 7 y 16 0 4u 5v 29 13. 4u 3v 21 0 8h 3k 7 0 14. 8h 5k 31 0 15. a b = 4a + b + 10 = 0 16. 2x + 5y 4 = 4x + 5y = 0 Solve the following simultaneous equations by any algebraic method. [Nos. 1722] b 2a 5 17. a b 7 m 2 n 1 18. m 5 2 n a 7b 13 19. 6a 7b 8 3s 5r 2 20. 5r 2 s y 3 2x 21. 2 y 33 5 x 5u 9v 2 0 22. 5u 9v 2 0 © Oxford University Press 2021 5.1 Consolidation Exercise 2A Chapter 5 23. Determine whether the following simultaneous equations have no solutions or more than one solution. x y 8 2 x y 1 (a) (b) x y 12 2 x y 1 3x y 2 (c) 3x y 2 x 4 y 1 0 (d) x 4 y 1 Solve the following simultaneous equations by any algebraic method. [Nos. 24–25] x 2 y 7 y 5 4x 24. 25. 2 y 7 x 4 x y 10 Level 2 Solve the following simultaneous equations by the method of elimination. [Nos. 2635] 3a 2b 13 26. a 3b 14 2h k 3 27. 3h 4k 10 3m 4n 2 28. 5m 2n 1 3 x 2 y 5 29. 7 x 6 y 1 3 x 10 y 16 30. 2 x 9 y 6 5 p 4q 3 31. 4 p 5q 6 2 r 5 s 8 32. 4 s 3r 34 a b 5 4 3 33. a b 7 3 2 34. 2x y = 4x + 3y 5 = 0 35. 5a 14 = 2a + 5b 17 = 2b © Oxford University Press 2021 5.2 Consolidation Exercise 2A Chapter 5 Solve the following simultaneous equations by any algebraic method. [Nos. 3645] 2 x y 3 0 36. 3x 4 y 1 0 2 x 5 y 37. 6 x 10 y 3 2h k 5 38. 3 h 3k 1 4 2 m 3 n 39. 7 4 m 2n 10 0 7 p 0.5q 10 40. 0.5 p q 20 x 6 y 4 41. 2 3 x y 5 5 5 2 x 3 y 4 42. 4 x 6 y 8 24 x 18 y 11 43. 7 8 x 6 y 0 44. 7k + 4(2 h) = 7h + 4k 14 = 0 45. 6r + 2s + 5(1 r) = 3(r + 2s) + 15 = 0 © Oxford University Press 2021 5.3 Consolidation Exercise 2A Chapter 5 Answers Consolidation Exercise 5D 1. x = 2, y = 6 3. x = 11, y = 6 5. x = 4, y = 1 7. c = 4, d = 13 9. x = 6, y = 19 11. x = 1, y = 3 13. u = 6, v = 1 15. a = 2, b = 2 17. a = 4, b = 3 19. a = 1, b = 2 21. x = 3, y = 9 2. x = 3, y = 7 4. x = 1, y = 3 6. x = 1, y = 2 8. h = 37, k = 3 10. x = 7, y = 7 12. x = 3, y = 1 14. h = 2, k = 3 8 16. x = 2, y = 5 3 18. m = 2, n = 2 2 20. r = , s = 0 5 2 22. u = 0, v = 9 23. (a) no solutions (b) more than one solution (c) no solutions (d) more than one solution 24. no solutions 25. more than one solution 26. a = 1, b = 5 27. h = 2, k = 1 1 28. m = 0, n = 29. x = 1, y = 1 2 30. x = 12, y = 2 31. p = 1, q = 2 32. r = 6, s = 4 33. a = 12, b = 6 1 34. x = , y = 1 35. a = 4, b = 3 2 3 3 36. x = 1, y = 1 37. x = , y = 5 2 7 38. h = 7, k = 1 39. m = , n = 4 2 11 40. p = 16, q = 12 41. x = 18, y = 3 42. more than one solution 43. no solutions 44. h = 2, k = 0 45. more than one solution © Oxford University Press 2021 5.4 Consolidation Exercise 2A Chapter 5