← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 134 · 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 = 23 and ab = 132, what is a² + b²?
  2. 2.Use (a − b)² = a² − 2ab + b² to find 56².
  3. 3.Use (a + b)(a − b) = a² − b² to find 78 × 62.
  4. 4.Use (a + b)² = a² + 2ab + b² to find 65².
  5. 5.Use (a − b)² = a² − 2ab + b² to find 99².
  6. 6.Use (a + b)² = a² + 2ab + b² to find 13².
  7. 7.Use (a + b)(a − b) = a² − b² to find 89 × 71.
  8. 8.Use a² − b² = (a + b)(a − b) to find 83² − 29².
  9. 9.Use (a − b)² = a² − 2ab + b² to find 11².
  10. 10.Use (a + b)² = a² + 2ab + b² to find 96².
  11. 11.Use (a + b)² = a² + 2ab + b² to find 25².
  12. 12.Use (a − b)² = a² − 2ab + b² to find 91².
  13. 13.Use (a + b)² = a² + 2ab + b² to find 11².
  14. 14.If a + b = 9 and ab = 14, what is a² + b²?
  15. 15.Use (a − b)² = a² − 2ab + b² to find 61².
  16. 16.Use a² − b² = (a + b)(a − b) to find 64² − 44².
  17. 17.Use (a − b)² = a² − 2ab + b² to find 55².
  18. 18.Find the value of x² + 2xy + y² when x = 14 and y = 4.
  19. 19.If a − b = 7 and ab = 60, what is a² + b²?
  20. 20.Use (a − b)² = a² − 2ab + b² to find 52².
  21. 21.Use (a − b)² = a² − 2ab + b² to find 94².
  22. 22.If a + b = 14 and ab = 45, what is a² + b²?
  23. 23.Use (a + b)(a − b) = a² − b² to find 28 × 12.
  24. 24.Use (a − b)² = a² − 2ab + b² to find 97².
  25. 25.Use (a + b)² = a² + 2ab + b² to find 75².
  26. 26.Find the value of x² − y² when x = 15 and y = 11.
  27. 27.Use (a − b)² = a² − 2ab + b² to find 96².
  28. 28.If a − b = 3 and ab = 10, what is a² + b²?
  29. 29.Use (a − b)² = a² − 2ab + b² to find 92².
  30. 30.Use (a + b)(a − b) = a² − b² to find 103 × 97.
  31. 31.Find the value of x² − y² when x = 12 and y = 7.
  32. 32.Use (a + b)² = a² + 2ab + b² to find 69².
  33. 33.Use a² − b² = (a + b)(a − b) to find 77² − 62².
  34. 34.Use (a − b)² = a² − 2ab + b² to find 49².
  35. 35.Use (a + b)(a − b) = a² − b² to find 77 × 63.
  36. 36.Use (a + b)² = a² + 2ab + b² to find 46².
  37. 37.If a + b = 9 and ab = 20, what is a² + b²?
  38. 38.If a + b = 3 and ab = 2, what is a² + b²?
  39. 39.Use (a + b)(a − b) = a² − b² to find 43 × 37.
  40. 40.Use a² − b² = (a + b)(a − b) to find 58² − 2².

Answer key

  1. 265
  2. 3136
  3. 4836
  4. 4225
  5. 9801
  6. 169
  7. 6319
  8. 6048
  9. 121
  10. 9216
  11. 625
  12. 8281
  13. 121
  14. 53
  15. 3721
  16. 2160
  17. 3025
  18. 324
  19. 169
  20. 2704
  21. 8836
  22. 106
  23. 336
  24. 9409
  25. 5625
  26. 104
  27. 9216
  28. 29
  29. 8464
  30. 9991
  31. 95
  32. 4761
  33. 2085
  34. 2401
  35. 4851
  36. 2116
  37. 41
  38. 5
  39. 1591
  40. 3360

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