← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 231 · 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.Find the value of x² − y² when x = 14 and y = 7.
  2. 2.Use a² − b² = (a + b)(a − b) to find 83² − 55².
  3. 3.Use (a + b)² = a² + 2ab + b² to find 23².
  4. 4.Find the value of x² − 2xy + y² when x = 13 and y = 2.
  5. 5.If a − b = 3 and ab = 54, what is a² + b²?
  6. 6.Find the value of x² + 2xy + y² when x = 11 and y = 6.
  7. 7.Use (a − b)² = a² − 2ab + b² to find 61².
  8. 8.Use (a − b)² = a² − 2ab + b² to find 33².
  9. 9.Use (a − b)² = a² − 2ab + b² to find 35².
  10. 10.If a + b = 10 and ab = 24, what is a² + b²?
  11. 11.Find the value of x² + 2xy + y² when x = 15 and y = 3.
  12. 12.Use (a − b)² = a² − 2ab + b² to find 36².
  13. 13.Use (a + b)(a − b) = a² − b² to find 31 × 29.
  14. 14.Use (a + b)(a − b) = a² − b² to find 107 × 93.
  15. 15.Find the value of x² + 2xy + y² when x = 4 and y = 1.
  16. 16.Use (a − b)² = a² − 2ab + b² to find 71².
  17. 17.Use (a − b)² = a² − 2ab + b² to find 87².
  18. 18.If a + b = 7 and ab = 6, what is a² + b²?
  19. 19.If a + b = 3 and ab = 2, what is a² + b²?
  20. 20.If a − b = 2 and ab = 80, what is a² + b²?
  21. 21.Use (a + b)(a − b) = a² − b² to find 87 × 73.
  22. 22.Use (a + b)² = a² + 2ab + b² to find 102².
  23. 23.Use (a + b)(a − b) = a² − b² to find 83 × 77.
  24. 24.Use (a − b)² = a² − 2ab + b² to find 68².
  25. 25.Use (a − b)² = a² − 2ab + b² to find 31².
  26. 26.Use (a − b)² = a² − 2ab + b² to find 69².
  27. 27.Use (a + b)² = a² + 2ab + b² to find 101².
  28. 28.Find the value of x² − y² when x = 14 and y = 13.
  29. 29.Use a² − b² = (a + b)(a − b) to find 60² − 27².
  30. 30.Use (a − b)² = a² − 2ab + b² to find 67².
  31. 31.Use (a − b)² = a² − 2ab + b² to find 46².
  32. 32.If a − b = 4 and ab = 12, what is a² + b²?
  33. 33.Use (a + b)² = a² + 2ab + b² to find 82².
  34. 34.If a + b = 5 and ab = 4, what is a² + b²?
  35. 35.Find the value of x² − y² when x = 14 and y = 4.
  36. 36.Use (a + b)² = a² + 2ab + b² to find 13².
  37. 37.Find the value of x² + 2xy + y² when x = 7 and y = 1.
  38. 38.If a + b = 4 and ab = 3, what is a² + b²?
  39. 39.Use a² − b² = (a + b)(a − b) to find 69² − 51².
  40. 40.Use (a + b)² = a² + 2ab + b² to find 104².

Answer key

  1. 147
  2. 3864
  3. 529
  4. 121
  5. 117
  6. 289
  7. 3721
  8. 1089
  9. 1225
  10. 52
  11. 324
  12. 1296
  13. 899
  14. 9951
  15. 25
  16. 5041
  17. 7569
  18. 37
  19. 5
  20. 164
  21. 6351
  22. 10404
  23. 6391
  24. 4624
  25. 961
  26. 4761
  27. 10201
  28. 27
  29. 2871
  30. 4489
  31. 2116
  32. 40
  33. 6724
  34. 17
  35. 180
  36. 169
  37. 64
  38. 10
  39. 2160
  40. 10816

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