← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 659 · 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 99².
  2. 2.Use (a − b)² = a² − 2ab + b² to find 14².
  3. 3.Use (a + b)² = a² + 2ab + b² to find 53².
  4. 4.Use a² − b² = (a + b)(a − b) to find 32² − 24².
  5. 5.If a + b = 7 and ab = 10, what is a² + b²?
  6. 6.Use (a + b)² = a² + 2ab + b² to find 85².
  7. 7.Use a² − b² = (a + b)(a − b) to find 47² − 16².
  8. 8.Use (a − b)² = a² − 2ab + b² to find 31².
  9. 9.Use (a + b)² = a² + 2ab + b² to find 15².
  10. 10.Use (a − b)² = a² − 2ab + b² to find 75².
  11. 11.Use (a + b)(a − b) = a² − b² to find 33 × 27.
  12. 12.Use a² − b² = (a + b)(a − b) to find 26² − 24².
  13. 13.Use a² − b² = (a + b)(a − b) to find 62² − 39².
  14. 14.Use (a + b)² = a² + 2ab + b² to find 95².
  15. 15.If a + b = 4 and ab = 3, what is a² + b²?
  16. 16.Use (a + b)(a − b) = a² − b² to find 26 × 14.
  17. 17.Find the value of x² − y² when x = 5 and y = 1.
  18. 18.Use (a − b)² = a² − 2ab + b² to find 47².
  19. 19.Use (a − b)² = a² − 2ab + b² to find 11².
  20. 20.Find the value of x² + 2xy + y² when x = 5 and y = 4.
  21. 21.Use (a + b)² = a² + 2ab + b² to find 69².
  22. 22.Use (a − b)² = a² − 2ab + b² to find 58².
  23. 23.Use (a + b)² = a² + 2ab + b² to find 33².
  24. 24.Use (a + b)² = a² + 2ab + b² to find 36².
  25. 25.Find the value of x² − y² when x = 6 and y = 1.
  26. 26.Use (a + b)² = a² + 2ab + b² to find 87².
  27. 27.Find the value of x² + 2xy + y² when x = 10 and y = 1.
  28. 28.Find the value of x² + 2xy + y² when x = 8 and y = 3.
  29. 29.Use (a + b)² = a² + 2ab + b² to find 67².
  30. 30.Use (a + b)² = a² + 2ab + b² to find 28².
  31. 31.Use (a + b)² = a² + 2ab + b² to find 35².
  32. 32.Use (a − b)² = a² − 2ab + b² to find 12².
  33. 33.Use (a − b)² = a² − 2ab + b² to find 35².
  34. 34.Find the value of x² − 2xy + y² when x = 5 and y = 1.
  35. 35.Use (a + b)(a − b) = a² − b² to find 53 × 47.
  36. 36.Use (a + b)² = a² + 2ab + b² to find 96².
  37. 37.If a + b = 7 and ab = 6, what is a² + b²?
  38. 38.Use (a − b)² = a² − 2ab + b² to find 19².
  39. 39.Use (a + b)(a − b) = a² − b² to find 91 × 89.
  40. 40.Find the value of x² − 2xy + y² when x = 8 and y = 6.

Answer key

  1. 9801
  2. 196
  3. 2809
  4. 448
  5. 29
  6. 7225
  7. 1953
  8. 961
  9. 225
  10. 5625
  11. 891
  12. 100
  13. 2323
  14. 9025
  15. 10
  16. 364
  17. 24
  18. 2209
  19. 121
  20. 81
  21. 4761
  22. 3364
  23. 1089
  24. 1296
  25. 35
  26. 7569
  27. 121
  28. 121
  29. 4489
  30. 784
  31. 1225
  32. 144
  33. 1225
  34. 16
  35. 2491
  36. 9216
  37. 37
  38. 361
  39. 8099
  40. 4

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