← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 719 · 40 sums
TalentJR

The method (Split into easy parts): (a + b)² = a² + 2ab + b². (a − b)² = a² − 2ab + b². (a + b)(a − b) = a² − b²; so a² − b² = (a + b)(a − b). a² + b² = (a + b)² − 2ab = (a − b)² + 2ab.

NameDateTime takenScore ___ / 40
  1. 1.Use a² − b² = (a + b)(a − b) to find 69² − 24².
  2. 2.If a − b = 2 and ab = 35, what is a² + b²?
  3. 3.Use (a − b)² = a² − 2ab + b² to find 24².
  4. 4.Use (a + b)(a − b) = a² − b² to find 56 × 44.
  5. 5.Find the value of x² − y² when x = 3 and y = 1.
  6. 6.Find the value of x² − 2xy + y² when x = 13 and y = 2.
  7. 7.Use (a + b)(a − b) = a² − b² to find 58 × 42.
  8. 8.Find the value of x² + 2xy + y² when x = 5 and y = 2.
  9. 9.Use (a − b)² = a² − 2ab + b² to find 94².
  10. 10.Use (a + b)² = a² + 2ab + b² to find 17².
  11. 11.Find the value of x² − y² when x = 14 and y = 5.
  12. 12.Find the value of x² + 2xy + y² when x = 14 and y = 13.
  13. 13.Find the value of x² + 2xy + y² when x = 5 and y = 4.
  14. 14.Use (a + b)(a − b) = a² − b² to find 43 × 37.
  15. 15.Find the value of x² + 2xy + y² when x = 12 and y = 11.
  16. 16.Use a² − b² = (a + b)(a − b) to find 35² − 1².
  17. 17.Use (a + b)² = a² + 2ab + b² to find 79².
  18. 18.Find the value of x² + 2xy + y² when x = 14 and y = 11.
  19. 19.Find the value of x² − y² when x = 9 and y = 4.
  20. 20.If a − b = 7 and ab = 8, what is a² + b²?
  21. 21.Find the value of x² + 2xy + y² when x = 3 and y = 1.
  22. 22.Use (a − b)² = a² − 2ab + b² to find 79².
  23. 23.If a + b = 7 and ab = 6, what is a² + b²?
  24. 24.Use a² − b² = (a + b)(a − b) to find 53² − 11².
  25. 25.If a − b = 7 and ab = 18, what is a² + b²?
  26. 26.Use a² − b² = (a + b)(a − b) to find 37² − 15².
  27. 27.Use (a − b)² = a² − 2ab + b² to find 33².
  28. 28.Find the value of x² − 2xy + y² when x = 6 and y = 1.
  29. 29.Use a² − b² = (a + b)(a − b) to find 56² − 16².
  30. 30.Use (a + b)² = a² + 2ab + b² to find 85².
  31. 31.Use a² − b² = (a + b)(a − b) to find 99² − 50².
  32. 32.Use (a − b)² = a² − 2ab + b² to find 23².
  33. 33.Use (a + b)² = a² + 2ab + b² to find 97².
  34. 34.If a + b = 9 and ab = 20, what is a² + b²?
  35. 35.Use a² − b² = (a + b)(a − b) to find 67² − 23².
  36. 36.Use (a + b)(a − b) = a² − b² to find 76 × 64.
  37. 37.Use (a + b)(a − b) = a² − b² to find 38 × 22.
  38. 38.Use (a + b)² = a² + 2ab + b² to find 102².
  39. 39.Use (a + b)(a − b) = a² − b² to find 73 × 67.
  40. 40.Find the value of x² + 2xy + y² when x = 4 and y = 3.

Answer key

  1. 4185
  2. 74
  3. 576
  4. 2464
  5. 8
  6. 121
  7. 2436
  8. 49
  9. 8836
  10. 289
  11. 171
  12. 729
  13. 81
  14. 1591
  15. 529
  16. 1224
  17. 6241
  18. 625
  19. 65
  20. 65
  21. 16
  22. 6241
  23. 37
  24. 2688
  25. 85
  26. 1144
  27. 1089
  28. 25
  29. 2880
  30. 7225
  31. 7301
  32. 529
  33. 9409
  34. 41
  35. 3960
  36. 4864
  37. 836
  38. 10404
  39. 4891
  40. 49

Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets