← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 458 · 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 = 13 and y = 10.
  2. 2.Use (a + b)² = a² + 2ab + b² to find 38².
  3. 3.If a − b = 5 and ab = 24, what is a² + b²?
  4. 4.Find the value of x² + 2xy + y² when x = 12 and y = 8.
  5. 5.Use (a + b)² = a² + 2ab + b² to find 18².
  6. 6.Use (a + b)(a − b) = a² − b² to find 102 × 98.
  7. 7.If a − b = 1 and ab = 6, what is a² + b²?
  8. 8.Use a² − b² = (a + b)(a − b) to find 23² − 21².
  9. 9.Use (a − b)² = a² − 2ab + b² to find 12².
  10. 10.Use (a + b)² = a² + 2ab + b² to find 77².
  11. 11.If a + b = 8 and ab = 15, what is a² + b²?
  12. 12.Use (a − b)² = a² − 2ab + b² to find 49².
  13. 13.Use (a − b)² = a² − 2ab + b² to find 92².
  14. 14.If a + b = 4 and ab = 3, what is a² + b²?
  15. 15.Use a² − b² = (a + b)(a − b) to find 91² − 7².
  16. 16.If a + b = 22 and ab = 120, what is a² + b²?
  17. 17.If a + b = 5 and ab = 4, what is a² + b²?
  18. 18.Use (a + b)² = a² + 2ab + b² to find 22².
  19. 19.Use (a + b)² = a² + 2ab + b² to find 56².
  20. 20.Use a² − b² = (a + b)(a − b) to find 29² − 24².
  21. 21.Use a² − b² = (a + b)(a − b) to find 88² − 62².
  22. 22.Use (a + b)² = a² + 2ab + b² to find 86².
  23. 23.Find the value of x² − 2xy + y² when x = 6 and y = 2.
  24. 24.Find the value of x² − y² when x = 13 and y = 3.
  25. 25.Use (a + b)² = a² + 2ab + b² to find 43².
  26. 26.Use (a + b)² = a² + 2ab + b² to find 15².
  27. 27.Find the value of x² + 2xy + y² when x = 10 and y = 7.
  28. 28.Use (a + b)² = a² + 2ab + b² to find 12².
  29. 29.Use (a − b)² = a² − 2ab + b² to find 21².
  30. 30.Use a² − b² = (a + b)(a − b) to find 34² − 7².
  31. 31.Use (a − b)² = a² − 2ab + b² to find 11².
  32. 32.Use (a − b)² = a² − 2ab + b² to find 64².
  33. 33.Find the value of x² + 2xy + y² when x = 4 and y = 3.
  34. 34.Use (a + b)² = a² + 2ab + b² to find 84².
  35. 35.Use (a + b)² = a² + 2ab + b² to find 48².
  36. 36.Use (a + b)² = a² + 2ab + b² to find 62².
  37. 37.Use (a + b)² = a² + 2ab + b² to find 79².
  38. 38.If a + b = 13 and ab = 12, what is a² + b²?
  39. 39.Use (a − b)² = a² − 2ab + b² to find 86².
  40. 40.Use (a + b)² = a² + 2ab + b² to find 105².

Answer key

  1. 69
  2. 1444
  3. 73
  4. 400
  5. 324
  6. 9996
  7. 13
  8. 88
  9. 144
  10. 5929
  11. 34
  12. 2401
  13. 8464
  14. 10
  15. 8232
  16. 244
  17. 17
  18. 484
  19. 3136
  20. 265
  21. 3900
  22. 7396
  23. 16
  24. 160
  25. 1849
  26. 225
  27. 289
  28. 144
  29. 441
  30. 1107
  31. 121
  32. 4096
  33. 49
  34. 7056
  35. 2304
  36. 3844
  37. 6241
  38. 145
  39. 7396
  40. 11025

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