← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 362 · 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 (a − b)² = a² − 2ab + b² to find 83².
  2. 2.Find the value of x² + 2xy + y² when x = 6 and y = 3.
  3. 3.Use (a − b)² = a² − 2ab + b² to find 87².
  4. 4.If a − b = 4 and ab = 5, what is a² + b²?
  5. 5.Use (a + b)(a − b) = a² − b² to find 26 × 14.
  6. 6.If a − b = 1 and ab = 42, what is a² + b²?
  7. 7.Use a² − b² = (a + b)(a − b) to find 83² − 73².
  8. 8.Use a² − b² = (a + b)(a − b) to find 88² − 69².
  9. 9.Use a² − b² = (a + b)(a − b) to find 96² − 75².
  10. 10.Use (a − b)² = a² − 2ab + b² to find 17².
  11. 11.Use (a − b)² = a² − 2ab + b² to find 36².
  12. 12.Use a² − b² = (a + b)(a − b) to find 99² − 3².
  13. 13.Use (a + b)(a − b) = a² − b² to find 23 × 17.
  14. 14.Use a² − b² = (a + b)(a − b) to find 91² − 17².
  15. 15.Use (a + b)(a − b) = a² − b² to find 49 × 31.
  16. 16.Use (a + b)² = a² + 2ab + b² to find 106².
  17. 17.Find the value of x² − 2xy + y² when x = 11 and y = 7.
  18. 18.Use a² − b² = (a + b)(a − b) to find 50² − 3².
  19. 19.Use (a + b)² = a² + 2ab + b² to find 56².
  20. 20.Use (a + b)(a − b) = a² − b² to find 55 × 45.
  21. 21.Use (a + b)(a − b) = a² − b² to find 24 × 16.
  22. 22.Use (a + b)² = a² + 2ab + b² to find 94².
  23. 23.Use (a + b)(a − b) = a² − b² to find 58 × 42.
  24. 24.If a − b = 9 and ab = 10, what is a² + b²?
  25. 25.Use (a + b)(a − b) = a² − b² to find 73 × 67.
  26. 26.If a + b = 6 and ab = 8, what is a² + b²?
  27. 27.Find the value of x² + 2xy + y² when x = 11 and y = 1.
  28. 28.Use (a + b)² = a² + 2ab + b² to find 41².
  29. 29.Use (a − b)² = a² − 2ab + b² to find 96².
  30. 30.Use a² − b² = (a + b)(a − b) to find 93² − 43².
  31. 31.Use a² − b² = (a + b)(a − b) to find 89² − 83².
  32. 32.Find the value of x² + 2xy + y² when x = 10 and y = 5.
  33. 33.Use a² − b² = (a + b)(a − b) to find 61² − 31².
  34. 34.Use (a − b)² = a² − 2ab + b² to find 11².
  35. 35.Find the value of x² − y² when x = 13 and y = 7.
  36. 36.Use a² − b² = (a + b)(a − b) to find 35² − 5².
  37. 37.Use (a − b)² = a² − 2ab + b² to find 75².
  38. 38.Use (a + b)² = a² + 2ab + b² to find 83².
  39. 39.Use (a + b)(a − b) = a² − b² to find 47 × 33.
  40. 40.Use (a + b)² = a² + 2ab + b² to find 35².

Answer key

  1. 6889
  2. 81
  3. 7569
  4. 26
  5. 364
  6. 85
  7. 1560
  8. 2983
  9. 3591
  10. 289
  11. 1296
  12. 9792
  13. 391
  14. 7992
  15. 1519
  16. 11236
  17. 16
  18. 2491
  19. 3136
  20. 2475
  21. 384
  22. 8836
  23. 2436
  24. 101
  25. 4891
  26. 20
  27. 144
  28. 1681
  29. 9216
  30. 6800
  31. 1032
  32. 225
  33. 2760
  34. 121
  35. 120
  36. 1200
  37. 5625
  38. 6889
  39. 1551
  40. 1225

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