← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 859 · 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 − 2xy + y² when x = 7 and y = 1.
  2. 2.If a + b = 14 and ab = 40, what is a² + b²?
  3. 3.Use a² − b² = (a + b)(a − b) to find 56² − 21².
  4. 4.Use a² − b² = (a + b)(a − b) to find 61² − 7².
  5. 5.If a + b = 14 and ab = 48, what is a² + b²?
  6. 6.If a − b = 2 and ab = 3, what is a² + b²?
  7. 7.Use (a − b)² = a² − 2ab + b² to find 34².
  8. 8.Use (a + b)(a − b) = a² − b² to find 64 × 56.
  9. 9.Use (a − b)² = a² − 2ab + b² to find 11².
  10. 10.If a + b = 9 and ab = 20, what is a² + b²?
  11. 11.Use (a + b)² = a² + 2ab + b² to find 17².
  12. 12.If a + b = 16 and ab = 63, what is a² + b²?
  13. 13.Find the value of x² + 2xy + y² when x = 12 and y = 8.
  14. 14.Use a² − b² = (a + b)(a − b) to find 22² − 3².
  15. 15.Use a² − b² = (a + b)(a − b) to find 24² − 13².
  16. 16.Use a² − b² = (a + b)(a − b) to find 84² − 18².
  17. 17.Use (a + b)(a − b) = a² − b² to find 56 × 44.
  18. 18.Use (a − b)² = a² − 2ab + b² to find 74².
  19. 19.Use a² − b² = (a + b)(a − b) to find 62² − 27².
  20. 20.Use (a − b)² = a² − 2ab + b² to find 71².
  21. 21.Find the value of x² + 2xy + y² when x = 3 and y = 2.
  22. 22.If a + b = 9 and ab = 18, what is a² + b²?
  23. 23.Find the value of x² − y² when x = 13 and y = 8.
  24. 24.Use (a − b)² = a² − 2ab + b² to find 89².
  25. 25.Find the value of x² + 2xy + y² when x = 15 and y = 5.
  26. 26.Use (a + b)(a − b) = a² − b² to find 99 × 81.
  27. 27.Use a² − b² = (a + b)(a − b) to find 31² − 6².
  28. 28.If a + b = 9 and ab = 8, what is a² + b²?
  29. 29.If a − b = 4 and ab = 12, what is a² + b²?
  30. 30.Use (a − b)² = a² − 2ab + b² to find 16².
  31. 31.Find the value of x² + 2xy + y² when x = 4 and y = 1.
  32. 32.Use (a + b)(a − b) = a² − b² to find 93 × 87.
  33. 33.Use (a + b)² = a² + 2ab + b² to find 12².
  34. 34.Use (a + b)(a − b) = a² − b² to find 83 × 77.
  35. 35.Use a² − b² = (a + b)(a − b) to find 27² − 4².
  36. 36.Use a² − b² = (a + b)(a − b) to find 57² − 35².
  37. 37.Use (a + b)(a − b) = a² − b² to find 39 × 21.
  38. 38.Use (a + b)(a − b) = a² − b² to find 43 × 37.
  39. 39.Use a² − b² = (a + b)(a − b) to find 80² − 8².
  40. 40.Use (a − b)² = a² − 2ab + b² to find 37².

Answer key

  1. 36
  2. 116
  3. 2695
  4. 3672
  5. 100
  6. 10
  7. 1156
  8. 3584
  9. 121
  10. 41
  11. 289
  12. 130
  13. 400
  14. 475
  15. 407
  16. 6732
  17. 2464
  18. 5476
  19. 3115
  20. 5041
  21. 25
  22. 45
  23. 105
  24. 7921
  25. 400
  26. 8019
  27. 925
  28. 65
  29. 40
  30. 256
  31. 25
  32. 8091
  33. 144
  34. 6391
  35. 713
  36. 2024
  37. 819
  38. 1591
  39. 6336
  40. 1369

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