← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 295 · 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)(a − b) = a² − b² to find 24 × 16.
  2. 2.Use a² − b² = (a + b)(a − b) to find 27² − 4².
  3. 3.Use (a + b)² = a² + 2ab + b² to find 101².
  4. 4.Use (a + b)(a − b) = a² − b² to find 104 × 96.
  5. 5.Use a² − b² = (a + b)(a − b) to find 25² − 10².
  6. 6.Find the value of x² + 2xy + y² when x = 10 and y = 9.
  7. 7.Use (a + b)² = a² + 2ab + b² to find 62².
  8. 8.If a − b = 9 and ab = 36, what is a² + b²?
  9. 9.Use a² − b² = (a + b)(a − b) to find 29² − 23².
  10. 10.Use (a − b)² = a² − 2ab + b² to find 85².
  11. 11.Find the value of x² − y² when x = 12 and y = 5.
  12. 12.If a + b = 17 and ab = 70, what is a² + b²?
  13. 13.Use (a − b)² = a² − 2ab + b² to find 87².
  14. 14.Use (a + b)(a − b) = a² − b² to find 88 × 72.
  15. 15.Find the value of x² + 2xy + y² when x = 6 and y = 2.
  16. 16.Use (a + b)² = a² + 2ab + b² to find 35².
  17. 17.Use (a − b)² = a² − 2ab + b² to find 77².
  18. 18.Use a² − b² = (a + b)(a − b) to find 38² − 11².
  19. 19.Use (a − b)² = a² − 2ab + b² to find 13².
  20. 20.Find the value of x² − 2xy + y² when x = 4 and y = 1.
  21. 21.If a + b = 19 and ab = 90, what is a² + b²?
  22. 22.Use (a + b)² = a² + 2ab + b² to find 75².
  23. 23.Use a² − b² = (a + b)(a − b) to find 96² − 21².
  24. 24.Use (a + b)² = a² + 2ab + b² to find 61².
  25. 25.Use (a − b)² = a² − 2ab + b² to find 31².
  26. 26.If a − b = 1 and ab = 6, what is a² + b²?
  27. 27.Use (a + b)(a − b) = a² − b² to find 83 × 77.
  28. 28.Use (a − b)² = a² − 2ab + b² to find 66².
  29. 29.Find the value of x² − y² when x = 4 and y = 3.
  30. 30.If a − b = 1 and ab = 12, what is a² + b²?
  31. 31.Use (a + b)(a − b) = a² − b² to find 93 × 87.
  32. 32.Use (a + b)(a − b) = a² − b² to find 59 × 41.
  33. 33.Use (a − b)² = a² − 2ab + b² to find 73².
  34. 34.Use a² − b² = (a + b)(a − b) to find 27² − 3².
  35. 35.Use (a − b)² = a² − 2ab + b² to find 54².
  36. 36.Use (a − b)² = a² − 2ab + b² to find 58².
  37. 37.Use (a + b)(a − b) = a² − b² to find 74 × 66.
  38. 38.Use a² − b² = (a + b)(a − b) to find 62² − 44².
  39. 39.If a + b = 15 and ab = 54, what is a² + b²?
  40. 40.Use (a + b)² = a² + 2ab + b² to find 102².

Answer key

  1. 384
  2. 713
  3. 10201
  4. 9984
  5. 525
  6. 361
  7. 3844
  8. 153
  9. 312
  10. 7225
  11. 119
  12. 149
  13. 7569
  14. 6336
  15. 64
  16. 1225
  17. 5929
  18. 1323
  19. 169
  20. 9
  21. 181
  22. 5625
  23. 8775
  24. 3721
  25. 961
  26. 13
  27. 6391
  28. 4356
  29. 7
  30. 25
  31. 8091
  32. 2419
  33. 5329
  34. 720
  35. 2916
  36. 3364
  37. 4884
  38. 1908
  39. 117
  40. 10404

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