← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 372 · 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.Find the value of x² − y² when x = 7 and y = 2.
  2. 2.Use (a − b)² = a² − 2ab + b² to find 47².
  3. 3.Find the value of x² − 2xy + y² when x = 11 and y = 3.
  4. 4.Use a² − b² = (a + b)(a − b) to find 37² − 16².
  5. 5.Use (a + b)(a − b) = a² − b² to find 94 × 86.
  6. 6.Use a² − b² = (a + b)(a − b) to find 75² − 35².
  7. 7.Use (a + b)² = a² + 2ab + b² to find 32².
  8. 8.If a + b = 9 and ab = 18, what is a² + b²?
  9. 9.Use (a + b)² = a² + 2ab + b² to find 22².
  10. 10.Use a² − b² = (a + b)(a − b) to find 37² − 4².
  11. 11.Use (a + b)² = a² + 2ab + b² to find 28².
  12. 12.Use (a − b)² = a² − 2ab + b² to find 81².
  13. 13.Use a² − b² = (a + b)(a − b) to find 60² − 18².
  14. 14.Find the value of x² + 2xy + y² when x = 14 and y = 3.
  15. 15.Use (a − b)² = a² − 2ab + b² to find 33².
  16. 16.Use (a + b)² = a² + 2ab + b² to find 87².
  17. 17.If a + b = 9 and ab = 14, what is a² + b²?
  18. 18.Use (a − b)² = a² − 2ab + b² to find 96².
  19. 19.Use (a + b)(a − b) = a² − b² to find 58 × 42.
  20. 20.Use (a + b)(a − b) = a² − b² to find 62 × 58.
  21. 21.Use (a − b)² = a² − 2ab + b² to find 13².
  22. 22.Use (a + b)(a − b) = a² − b² to find 75 × 65.
  23. 23.Use a² − b² = (a + b)(a − b) to find 76² − 50².
  24. 24.If a − b = 2 and ab = 3, what is a² + b²?
  25. 25.Find the value of x² − y² when x = 5 and y = 1.
  26. 26.Use a² − b² = (a + b)(a − b) to find 79² − 12².
  27. 27.Use (a + b)(a − b) = a² − b² to find 86 × 74.
  28. 28.Find the value of x² + 2xy + y² when x = 6 and y = 1.
  29. 29.Use a² − b² = (a + b)(a − b) to find 54² − 33².
  30. 30.Use (a + b)(a − b) = a² − b² to find 79 × 61.
  31. 31.If a + b = 6 and ab = 5, what is a² + b²?
  32. 32.Use (a − b)² = a² − 2ab + b² to find 16².
  33. 33.Use (a + b)(a − b) = a² − b² to find 91 × 89.
  34. 34.Use a² − b² = (a + b)(a − b) to find 35² − 34².
  35. 35.Find the value of x² − y² when x = 12 and y = 6.
  36. 36.Use (a − b)² = a² − 2ab + b² to find 43².
  37. 37.Use (a − b)² = a² − 2ab + b² to find 18².
  38. 38.Use a² − b² = (a + b)(a − b) to find 35² − 33².
  39. 39.If a − b = 7 and ab = 30, what is a² + b²?
  40. 40.Use (a + b)² = a² + 2ab + b² to find 39².

Answer key

  1. 45
  2. 2209
  3. 64
  4. 1113
  5. 8084
  6. 4400
  7. 1024
  8. 45
  9. 484
  10. 1353
  11. 784
  12. 6561
  13. 3276
  14. 289
  15. 1089
  16. 7569
  17. 53
  18. 9216
  19. 2436
  20. 3596
  21. 169
  22. 4875
  23. 3276
  24. 10
  25. 24
  26. 6097
  27. 6364
  28. 49
  29. 1827
  30. 4819
  31. 26
  32. 256
  33. 8099
  34. 69
  35. 108
  36. 1849
  37. 324
  38. 136
  39. 109
  40. 1521

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