← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 926 · 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 103².
  2. 2.Use (a − b)² = a² − 2ab + b² to find 62².
  3. 3.Use a² − b² = (a + b)(a − b) to find 85² − 79².
  4. 4.Find the value of x² − 2xy + y² when x = 11 and y = 2.
  5. 5.Use (a − b)² = a² − 2ab + b² to find 22².
  6. 6.Use (a − b)² = a² − 2ab + b² to find 36².
  7. 7.Find the value of x² + 2xy + y² when x = 7 and y = 4.
  8. 8.If a − b = 4 and ab = 5, what is a² + b²?
  9. 9.Find the value of x² − y² when x = 14 and y = 3.
  10. 10.Find the value of x² − y² when x = 13 and y = 6.
  11. 11.Use a² − b² = (a + b)(a − b) to find 68² − 35².
  12. 12.If a + b = 11 and ab = 28, what is a² + b²?
  13. 13.Use (a + b)² = a² + 2ab + b² to find 97².
  14. 14.Find the value of x² − y² when x = 3 and y = 2.
  15. 15.Use (a + b)(a − b) = a² − b² to find 38 × 22.
  16. 16.If a + b = 18 and ab = 80, what is a² + b²?
  17. 17.Use (a − b)² = a² − 2ab + b² to find 76².
  18. 18.Use (a + b)(a − b) = a² − b² to find 73 × 67.
  19. 19.Use (a + b)(a − b) = a² − b² to find 63 × 57.
  20. 20.Use (a + b)(a − b) = a² − b² to find 35 × 25.
  21. 21.Use (a − b)² = a² − 2ab + b² to find 87².
  22. 22.Find the value of x² − 2xy + y² when x = 13 and y = 10.
  23. 23.Use (a + b)(a − b) = a² − b² to find 99 × 81.
  24. 24.Use a² − b² = (a + b)(a − b) to find 57² − 32².
  25. 25.Find the value of x² + 2xy + y² when x = 11 and y = 7.
  26. 26.Use (a + b)(a − b) = a² − b² to find 55 × 45.
  27. 27.Use a² − b² = (a + b)(a − b) to find 35² − 34².
  28. 28.If a + b = 10 and ab = 21, what is a² + b²?
  29. 29.If a + b = 6 and ab = 8, what is a² + b²?
  30. 30.Use (a + b)(a − b) = a² − b² to find 65 × 55.
  31. 31.Find the value of x² − 2xy + y² when x = 5 and y = 1.
  32. 32.Use a² − b² = (a + b)(a − b) to find 68² − 57².
  33. 33.If a − b = 2 and ab = 3, what is a² + b²?
  34. 34.Use (a − b)² = a² − 2ab + b² to find 37².
  35. 35.Use a² − b² = (a + b)(a − b) to find 97² − 90².
  36. 36.Find the value of x² + 2xy + y² when x = 4 and y = 3.
  37. 37.Use a² − b² = (a + b)(a − b) to find 51² − 21².
  38. 38.Use (a − b)² = a² − 2ab + b² to find 19².
  39. 39.Find the value of x² − 2xy + y² when x = 6 and y = 3.
  40. 40.Use (a + b)(a − b) = a² − b² to find 44 × 36.

Answer key

  1. 10609
  2. 3844
  3. 984
  4. 81
  5. 484
  6. 1296
  7. 121
  8. 26
  9. 187
  10. 133
  11. 3399
  12. 65
  13. 9409
  14. 5
  15. 836
  16. 164
  17. 5776
  18. 4891
  19. 3591
  20. 875
  21. 7569
  22. 9
  23. 8019
  24. 2225
  25. 324
  26. 2475
  27. 69
  28. 58
  29. 20
  30. 3575
  31. 16
  32. 1375
  33. 10
  34. 1369
  35. 1309
  36. 49
  37. 2160
  38. 361
  39. 9
  40. 1584

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