← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 98 · 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 16².
  2. 2.Find the value of x² + 2xy + y² when x = 13 and y = 8.
  3. 3.Use (a − b)² = a² − 2ab + b² to find 17².
  4. 4.Use (a + b)(a − b) = a² − b² to find 43 × 37.
  5. 5.Use (a + b)(a − b) = a² − b² to find 21 × 19.
  6. 6.Use a² − b² = (a + b)(a − b) to find 68² − 27².
  7. 7.Use a² − b² = (a + b)(a − b) to find 55² − 54².
  8. 8.Use a² − b² = (a + b)(a − b) to find 43² − 35².
  9. 9.Use (a + b)² = a² + 2ab + b² to find 79².
  10. 10.Find the value of x² + 2xy + y² when x = 3 and y = 1.
  11. 11.Use (a + b)(a − b) = a² − b² to find 48 × 32.
  12. 12.Use (a + b)² = a² + 2ab + b² to find 29².
  13. 13.Use (a + b)² = a² + 2ab + b² to find 41².
  14. 14.If a + b = 14 and ab = 33, what is a² + b²?
  15. 15.Use a² − b² = (a + b)(a − b) to find 83² − 27².
  16. 16.Use (a − b)² = a² − 2ab + b² to find 75².
  17. 17.Use (a + b)(a − b) = a² − b² to find 98 × 82.
  18. 18.Use (a + b)² = a² + 2ab + b² to find 31².
  19. 19.Use (a + b)² = a² + 2ab + b² to find 11².
  20. 20.Use (a + b)² = a² + 2ab + b² to find 71².
  21. 21.Use (a − b)² = a² − 2ab + b² to find 31².
  22. 22.Use (a − b)² = a² − 2ab + b² to find 51².
  23. 23.If a − b = 8 and ab = 9, what is a² + b²?
  24. 24.Find the value of x² − y² when x = 4 and y = 1.
  25. 25.Find the value of x² − y² when x = 8 and y = 4.
  26. 26.If a + b = 7 and ab = 10, what is a² + b²?
  27. 27.Find the value of x² − y² when x = 14 and y = 7.
  28. 28.If a − b = 1 and ab = 2, what is a² + b²?
  29. 29.Use (a − b)² = a² − 2ab + b² to find 19².
  30. 30.Use (a − b)² = a² − 2ab + b² to find 29².
  31. 31.Find the value of x² + 2xy + y² when x = 10 and y = 9.
  32. 32.Use a² − b² = (a + b)(a − b) to find 58² − 4².
  33. 33.Use (a − b)² = a² − 2ab + b² to find 96².
  34. 34.If a − b = 8 and ab = 33, what is a² + b²?
  35. 35.If a + b = 9 and ab = 20, what is a² + b²?
  36. 36.Use (a + b)² = a² + 2ab + b² to find 61².
  37. 37.Find the value of x² − 2xy + y² when x = 9 and y = 2.
  38. 38.If a − b = 2 and ab = 8, what is a² + b²?
  39. 39.Use (a − b)² = a² − 2ab + b² to find 84².
  40. 40.If a + b = 3 and ab = 2, what is a² + b²?

Answer key

  1. 256
  2. 441
  3. 289
  4. 1591
  5. 399
  6. 3895
  7. 109
  8. 624
  9. 6241
  10. 16
  11. 1536
  12. 841
  13. 1681
  14. 130
  15. 6160
  16. 5625
  17. 8036
  18. 961
  19. 121
  20. 5041
  21. 961
  22. 2601
  23. 82
  24. 15
  25. 48
  26. 29
  27. 147
  28. 5
  29. 361
  30. 841
  31. 361
  32. 3348
  33. 9216
  34. 130
  35. 41
  36. 3721
  37. 49
  38. 20
  39. 7056
  40. 5

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