← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 857 · 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.Use (a − b)² = a² − 2ab + b² to find 95².
  2. 2.Use (a + b)² = a² + 2ab + b² to find 94².
  3. 3.Use a² − b² = (a + b)(a − b) to find 64² − 21².
  4. 4.If a − b = 2 and ab = 8, what is a² + b²?
  5. 5.Use (a + b)² = a² + 2ab + b² to find 61².
  6. 6.Use (a − b)² = a² − 2ab + b² to find 14².
  7. 7.Use (a − b)² = a² − 2ab + b² to find 19².
  8. 8.Use (a − b)² = a² − 2ab + b² to find 45².
  9. 9.Use a² − b² = (a + b)(a − b) to find 34² − 9².
  10. 10.Find the value of x² − 2xy + y² when x = 7 and y = 3.
  11. 11.Use (a − b)² = a² − 2ab + b² to find 66².
  12. 12.Use a² − b² = (a + b)(a − b) to find 53² − 7².
  13. 13.Find the value of x² − 2xy + y² when x = 9 and y = 6.
  14. 14.Use (a − b)² = a² − 2ab + b² to find 33².
  15. 15.If a − b = 8 and ab = 9, what is a² + b²?
  16. 16.Find the value of x² − 2xy + y² when x = 9 and y = 1.
  17. 17.Find the value of x² − y² when x = 4 and y = 2.
  18. 18.Use (a − b)² = a² − 2ab + b² to find 76².
  19. 19.Use a² − b² = (a + b)(a − b) to find 91² − 37².
  20. 20.Use (a + b)(a − b) = a² − b² to find 23 × 17.
  21. 21.If a − b = 3 and ab = 4, what is a² + b²?
  22. 22.Use (a + b)² = a² + 2ab + b² to find 76².
  23. 23.Use (a − b)² = a² − 2ab + b² to find 72².
  24. 24.Use a² − b² = (a + b)(a − b) to find 54² − 31².
  25. 25.Use (a − b)² = a² − 2ab + b² to find 54².
  26. 26.Use (a + b)² = a² + 2ab + b² to find 44².
  27. 27.Use (a + b)(a − b) = a² − b² to find 29 × 11.
  28. 28.Use (a − b)² = a² − 2ab + b² to find 24².
  29. 29.Find the value of x² + 2xy + y² when x = 7 and y = 4.
  30. 30.If a − b = 8 and ab = 48, what is a² + b²?
  31. 31.Use (a + b)² = a² + 2ab + b² to find 82².
  32. 32.Use (a + b)(a − b) = a² − b² to find 27 × 13.
  33. 33.Use (a + b)(a − b) = a² − b² to find 84 × 76.
  34. 34.Find the value of x² + 2xy + y² when x = 6 and y = 4.
  35. 35.Find the value of x² + 2xy + y² when x = 14 and y = 11.
  36. 36.Use (a + b)² = a² + 2ab + b² to find 68².
  37. 37.Find the value of x² + 2xy + y² when x = 13 and y = 7.
  38. 38.If a + b = 3 and ab = 2, what is a² + b²?
  39. 39.Use (a − b)² = a² − 2ab + b² to find 75².
  40. 40.Find the value of x² + 2xy + y² when x = 11 and y = 8.

Answer key

  1. 9025
  2. 8836
  3. 3655
  4. 20
  5. 3721
  6. 196
  7. 361
  8. 2025
  9. 1075
  10. 16
  11. 4356
  12. 2760
  13. 9
  14. 1089
  15. 82
  16. 64
  17. 12
  18. 5776
  19. 6912
  20. 391
  21. 17
  22. 5776
  23. 5184
  24. 1955
  25. 2916
  26. 1936
  27. 319
  28. 576
  29. 121
  30. 160
  31. 6724
  32. 351
  33. 6384
  34. 100
  35. 625
  36. 4624
  37. 400
  38. 5
  39. 5625
  40. 361

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