← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 629 · 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 46².
  2. 2.Use (a − b)² = a² − 2ab + b² to find 12².
  3. 3.Use (a + b)² = a² + 2ab + b² to find 36².
  4. 4.Find the value of x² − 2xy + y² when x = 14 and y = 11.
  5. 5.Use a² − b² = (a + b)(a − b) to find 87² − 6².
  6. 6.Find the value of x² + 2xy + y² when x = 14 and y = 2.
  7. 7.Use a² − b² = (a + b)(a − b) to find 88² − 10².
  8. 8.Use (a + b)² = a² + 2ab + b² to find 77².
  9. 9.Find the value of x² + 2xy + y² when x = 15 and y = 11.
  10. 10.Use (a − b)² = a² − 2ab + b² to find 35².
  11. 11.Use a² − b² = (a + b)(a − b) to find 28² − 26².
  12. 12.Find the value of x² − 2xy + y² when x = 6 and y = 2.
  13. 13.Find the value of x² − y² when x = 13 and y = 4.
  14. 14.Use (a + b)² = a² + 2ab + b² to find 66².
  15. 15.If a − b = 3 and ab = 10, what is a² + b²?
  16. 16.Use (a − b)² = a² − 2ab + b² to find 13².
  17. 17.Use (a + b)² = a² + 2ab + b² to find 33².
  18. 18.If a − b = 1 and ab = 20, what is a² + b²?
  19. 19.If a − b = 7 and ab = 30, what is a² + b²?
  20. 20.Use (a + b)² = a² + 2ab + b² to find 19².
  21. 21.Find the value of x² − 2xy + y² when x = 15 and y = 4.
  22. 22.Use a² − b² = (a + b)(a − b) to find 94² − 54².
  23. 23.If a − b = 2 and ab = 3, what is a² + b²?
  24. 24.If a + b = 14 and ab = 24, what is a² + b²?
  25. 25.Find the value of x² − y² when x = 3 and y = 1.
  26. 26.If a + b = 19 and ab = 84, what is a² + b²?
  27. 27.Use (a + b)(a − b) = a² − b² to find 67 × 53.
  28. 28.Use (a − b)² = a² − 2ab + b² to find 95².
  29. 29.If a + b = 3 and ab = 2, what is a² + b²?
  30. 30.Use (a − b)² = a² − 2ab + b² to find 87².
  31. 31.Find the value of x² − 2xy + y² when x = 8 and y = 3.
  32. 32.Find the value of x² − y² when x = 3 and y = 2.
  33. 33.Use (a + b)(a − b) = a² − b² to find 65 × 55.
  34. 34.Use a² − b² = (a + b)(a − b) to find 87² − 55².
  35. 35.Use a² − b² = (a + b)(a − b) to find 48² − 30².
  36. 36.Use (a − b)² = a² − 2ab + b² to find 22².
  37. 37.Use (a + b)² = a² + 2ab + b² to find 63².
  38. 38.Use (a − b)² = a² − 2ab + b² to find 84².
  39. 39.Use (a + b)² = a² + 2ab + b² to find 106².
  40. 40.If a + b = 13 and ab = 30, what is a² + b²?

Answer key

  1. 2116
  2. 144
  3. 1296
  4. 9
  5. 7533
  6. 256
  7. 7644
  8. 5929
  9. 676
  10. 1225
  11. 108
  12. 16
  13. 153
  14. 4356
  15. 29
  16. 169
  17. 1089
  18. 41
  19. 109
  20. 361
  21. 121
  22. 5920
  23. 10
  24. 148
  25. 8
  26. 193
  27. 3551
  28. 9025
  29. 5
  30. 7569
  31. 25
  32. 5
  33. 3575
  34. 4544
  35. 1404
  36. 484
  37. 3969
  38. 7056
  39. 11236
  40. 109

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