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Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 673 · 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.If a + b = 15 and ab = 56, what is a² + b²?
  2. 2.Find the value of x² − y² when x = 11 and y = 6.
  3. 3.Use (a + b)(a − b) = a² − b² to find 91 × 89.
  4. 4.Find the value of x² + 2xy + y² when x = 5 and y = 1.
  5. 5.Find the value of x² − y² when x = 12 and y = 3.
  6. 6.Use (a + b)² = a² + 2ab + b² to find 59².
  7. 7.Use (a + b)² = a² + 2ab + b² to find 93².
  8. 8.If a − b = 4 and ab = 5, what is a² + b²?
  9. 9.Find the value of x² − y² when x = 5 and y = 2.
  10. 10.Use a² − b² = (a + b)(a − b) to find 61² − 36².
  11. 11.Use (a − b)² = a² − 2ab + b² to find 12².
  12. 12.Use (a + b)² = a² + 2ab + b² to find 109².
  13. 13.Find the value of x² + 2xy + y² when x = 11 and y = 7.
  14. 14.Use (a + b)² = a² + 2ab + b² to find 99².
  15. 15.Use (a − b)² = a² − 2ab + b² to find 47².
  16. 16.Use a² − b² = (a + b)(a − b) to find 49² − 23².
  17. 17.Use (a + b)(a − b) = a² − b² to find 48 × 32.
  18. 18.Find the value of x² − 2xy + y² when x = 6 and y = 1.
  19. 19.Use a² − b² = (a + b)(a − b) to find 37² − 12².
  20. 20.Find the value of x² + 2xy + y² when x = 7 and y = 3.
  21. 21.Use (a + b)² = a² + 2ab + b² to find 64².
  22. 22.If a − b = 1 and ab = 12, what is a² + b²?
  23. 23.Use a² − b² = (a + b)(a − b) to find 34² − 9².
  24. 24.Use (a + b)² = a² + 2ab + b² to find 91².
  25. 25.If a + b = 3 and ab = 2, what is a² + b²?
  26. 26.If a − b = 3 and ab = 40, what is a² + b²?
  27. 27.Use (a + b)(a − b) = a² − b² to find 32 × 28.
  28. 28.Use (a − b)² = a² − 2ab + b² to find 76².
  29. 29.Use (a + b)² = a² + 2ab + b² to find 58².
  30. 30.If a − b = 7 and ab = 44, what is a² + b²?
  31. 31.Use a² − b² = (a + b)(a − b) to find 28² − 25².
  32. 32.Use a² − b² = (a + b)(a − b) to find 42² − 7².
  33. 33.Use (a − b)² = a² − 2ab + b² to find 57².
  34. 34.Use (a − b)² = a² − 2ab + b² to find 11².
  35. 35.If a + b = 11 and ab = 30, what is a² + b²?
  36. 36.Use (a + b)(a − b) = a² − b² to find 87 × 73.
  37. 37.Use a² − b² = (a + b)(a − b) to find 24² − 19².
  38. 38.Use a² − b² = (a + b)(a − b) to find 58² − 11².
  39. 39.If a + b = 13 and ab = 40, what is a² + b²?
  40. 40.Find the value of x² + 2xy + y² when x = 10 and y = 4.

Answer key

  1. 113
  2. 85
  3. 8099
  4. 36
  5. 135
  6. 3481
  7. 8649
  8. 26
  9. 21
  10. 2425
  11. 144
  12. 11881
  13. 324
  14. 9801
  15. 2209
  16. 1872
  17. 1536
  18. 25
  19. 1225
  20. 100
  21. 4096
  22. 25
  23. 1075
  24. 8281
  25. 5
  26. 89
  27. 896
  28. 5776
  29. 3364
  30. 137
  31. 159
  32. 1715
  33. 3249
  34. 121
  35. 61
  36. 6351
  37. 215
  38. 3243
  39. 89
  40. 196

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