← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 702 · 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 − 2xy + y² when x = 8 and y = 7.
  2. 2.Use (a − b)² = a² − 2ab + b² to find 34².
  3. 3.If a + b = 10 and ab = 24, what is a² + b²?
  4. 4.Find the value of x² − y² when x = 5 and y = 3.
  5. 5.Use (a + b)² = a² + 2ab + b² to find 18².
  6. 6.Use (a + b)² = a² + 2ab + b² to find 54².
  7. 7.Use (a + b)² = a² + 2ab + b² to find 46².
  8. 8.Use a² − b² = (a + b)(a − b) to find 48² − 24².
  9. 9.Use (a − b)² = a² − 2ab + b² to find 74².
  10. 10.Find the value of x² − y² when x = 13 and y = 11.
  11. 11.Use (a + b)(a − b) = a² − b² to find 99 × 81.
  12. 12.Use a² − b² = (a + b)(a − b) to find 73² − 57².
  13. 13.Use a² − b² = (a + b)(a − b) to find 94² − 13².
  14. 14.Use (a + b)(a − b) = a² − b² to find 82 × 78.
  15. 15.Use (a + b)(a − b) = a² − b² to find 48 × 32.
  16. 16.Use (a − b)² = a² − 2ab + b² to find 85².
  17. 17.Use a² − b² = (a + b)(a − b) to find 86² − 26².
  18. 18.If a + b = 4 and ab = 3, what is a² + b²?
  19. 19.Use a² − b² = (a + b)(a − b) to find 22² − 15².
  20. 20.Find the value of x² − y² when x = 5 and y = 1.
  21. 21.Use (a − b)² = a² − 2ab + b² to find 49².
  22. 22.Use (a + b)² = a² + 2ab + b² to find 63².
  23. 23.Use a² − b² = (a + b)(a − b) to find 26² − 14².
  24. 24.Use (a + b)² = a² + 2ab + b² to find 69².
  25. 25.Use a² − b² = (a + b)(a − b) to find 30² − 27².
  26. 26.Use a² − b² = (a + b)(a − b) to find 76² − 15².
  27. 27.Use (a + b)² = a² + 2ab + b² to find 23².
  28. 28.Use (a − b)² = a² − 2ab + b² to find 23².
  29. 29.Use (a + b)² = a² + 2ab + b² to find 88².
  30. 30.If a + b = 3 and ab = 2, what is a² + b²?
  31. 31.Use (a − b)² = a² − 2ab + b² to find 28².
  32. 32.Use a² − b² = (a + b)(a − b) to find 47² − 45².
  33. 33.Use (a + b)(a − b) = a² − b² to find 51 × 49.
  34. 34.Use a² − b² = (a + b)(a − b) to find 39² − 5².
  35. 35.Use (a − b)² = a² − 2ab + b² to find 96².
  36. 36.Use (a + b)² = a² + 2ab + b² to find 109².
  37. 37.Use (a + b)(a − b) = a² − b² to find 66 × 54.
  38. 38.If a − b = 1 and ab = 56, what is a² + b²?
  39. 39.Use (a − b)² = a² − 2ab + b² to find 13².
  40. 40.Use a² − b² = (a + b)(a − b) to find 73² − 35².

Answer key

  1. 1
  2. 1156
  3. 52
  4. 16
  5. 324
  6. 2916
  7. 2116
  8. 1728
  9. 5476
  10. 48
  11. 8019
  12. 2080
  13. 8667
  14. 6396
  15. 1536
  16. 7225
  17. 6720
  18. 10
  19. 259
  20. 24
  21. 2401
  22. 3969
  23. 480
  24. 4761
  25. 171
  26. 5551
  27. 529
  28. 529
  29. 7744
  30. 5
  31. 784
  32. 184
  33. 2499
  34. 1496
  35. 9216
  36. 11881
  37. 3564
  38. 113
  39. 169
  40. 4104

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