← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 30 · 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 29².
  2. 2.Use (a − b)² = a² − 2ab + b² to find 56².
  3. 3.Use (a − b)² = a² − 2ab + b² to find 73².
  4. 4.Use (a + b)(a − b) = a² − b² to find 76 × 64.
  5. 5.Use a² − b² = (a + b)(a − b) to find 60² − 22².
  6. 6.If a − b = 3 and ab = 54, what is a² + b²?
  7. 7.Use a² − b² = (a + b)(a − b) to find 88² − 47².
  8. 8.Use (a + b)(a − b) = a² − b² to find 88 × 72.
  9. 9.Find the value of x² + 2xy + y² when x = 13 and y = 10.
  10. 10.Use a² − b² = (a + b)(a − b) to find 60² − 54².
  11. 11.Find the value of x² − 2xy + y² when x = 5 and y = 1.
  12. 12.Use (a + b)² = a² + 2ab + b² to find 26².
  13. 13.Use (a + b)(a − b) = a² − b² to find 31 × 29.
  14. 14.Use (a + b)² = a² + 2ab + b² to find 81².
  15. 15.Find the value of x² − 2xy + y² when x = 15 and y = 14.
  16. 16.Use (a + b)(a − b) = a² − b² to find 84 × 76.
  17. 17.Use (a − b)² = a² − 2ab + b² to find 33².
  18. 18.Use (a − b)² = a² − 2ab + b² to find 27².
  19. 19.Use (a + b)² = a² + 2ab + b² to find 86².
  20. 20.Use (a + b)(a − b) = a² − b² to find 62 × 58.
  21. 21.Use (a − b)² = a² − 2ab + b² to find 21².
  22. 22.Use (a + b)² = a² + 2ab + b² to find 66².
  23. 23.Use a² − b² = (a + b)(a − b) to find 22² − 11².
  24. 24.Use (a + b)² = a² + 2ab + b² to find 85².
  25. 25.Use a² − b² = (a + b)(a − b) to find 60² − 14².
  26. 26.Use (a + b)² = a² + 2ab + b² to find 22².
  27. 27.Use (a + b)(a − b) = a² − b² to find 35 × 25.
  28. 28.If a − b = 4 and ab = 21, what is a² + b²?
  29. 29.Use (a − b)² = a² − 2ab + b² to find 25².
  30. 30.Use (a − b)² = a² − 2ab + b² to find 98².
  31. 31.Use (a + b)² = a² + 2ab + b² to find 43².
  32. 32.Use (a − b)² = a² − 2ab + b² to find 88².
  33. 33.If a − b = 2 and ab = 24, what is a² + b²?
  34. 34.Use (a − b)² = a² − 2ab + b² to find 99².
  35. 35.Find the value of x² − y² when x = 7 and y = 2.
  36. 36.Use a² − b² = (a + b)(a − b) to find 60² − 6².
  37. 37.Use a² − b² = (a + b)(a − b) to find 30² − 22².
  38. 38.Use a² − b² = (a + b)(a − b) to find 62² − 61².
  39. 39.If a + b = 11 and ab = 24, what is a² + b²?
  40. 40.Use (a − b)² = a² − 2ab + b² to find 44².

Answer key

  1. 841
  2. 3136
  3. 5329
  4. 4864
  5. 3116
  6. 117
  7. 5535
  8. 6336
  9. 529
  10. 684
  11. 16
  12. 676
  13. 899
  14. 6561
  15. 1
  16. 6384
  17. 1089
  18. 729
  19. 7396
  20. 3596
  21. 441
  22. 4356
  23. 363
  24. 7225
  25. 3404
  26. 484
  27. 875
  28. 58
  29. 625
  30. 9604
  31. 1849
  32. 7744
  33. 52
  34. 9801
  35. 45
  36. 3564
  37. 416
  38. 123
  39. 73
  40. 1936

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