← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 523 · 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 a² − b² = (a + b)(a − b) to find 95² − 2².
  2. 2.Use (a − b)² = a² − 2ab + b² to find 63².
  3. 3.Use a² − b² = (a + b)(a − b) to find 87² − 41².
  4. 4.Use a² − b² = (a + b)(a − b) to find 43² − 28².
  5. 5.Use (a − b)² = a² − 2ab + b² to find 93².
  6. 6.Use a² − b² = (a + b)(a − b) to find 86² − 54².
  7. 7.Use (a + b)² = a² + 2ab + b² to find 82².
  8. 8.Find the value of x² − 2xy + y² when x = 4 and y = 1.
  9. 9.Use (a + b)(a − b) = a² − b² to find 59 × 41.
  10. 10.Use a² − b² = (a + b)(a − b) to find 47² − 29².
  11. 11.Use (a − b)² = a² − 2ab + b² to find 66².
  12. 12.Use a² − b² = (a + b)(a − b) to find 59² − 44².
  13. 13.Use (a + b)² = a² + 2ab + b² to find 76².
  14. 14.Use (a − b)² = a² − 2ab + b² to find 46².
  15. 15.Find the value of x² − y² when x = 10 and y = 9.
  16. 16.Use (a + b)² = a² + 2ab + b² to find 22².
  17. 17.Use (a − b)² = a² − 2ab + b² to find 69².
  18. 18.If a − b = 8 and ab = 9, what is a² + b²?
  19. 19.Use a² − b² = (a + b)(a − b) to find 79² − 2².
  20. 20.Find the value of x² − 2xy + y² when x = 5 and y = 4.
  21. 21.If a + b = 10 and ab = 9, what is a² + b²?
  22. 22.Find the value of x² − 2xy + y² when x = 9 and y = 3.
  23. 23.Find the value of x² − y² when x = 5 and y = 3.
  24. 24.Find the value of x² − 2xy + y² when x = 12 and y = 10.
  25. 25.Use (a − b)² = a² − 2ab + b² to find 25².
  26. 26.Use (a + b)² = a² + 2ab + b² to find 95².
  27. 27.If a + b = 23 and ab = 132, what is a² + b²?
  28. 28.Use (a − b)² = a² − 2ab + b² to find 41².
  29. 29.Use a² − b² = (a + b)(a − b) to find 51² − 5².
  30. 30.Find the value of x² + 2xy + y² when x = 3 and y = 2.
  31. 31.Use (a − b)² = a² − 2ab + b² to find 37².
  32. 32.Use (a + b)² = a² + 2ab + b² to find 62².
  33. 33.Find the value of x² − y² when x = 11 and y = 2.
  34. 34.Use (a − b)² = a² − 2ab + b² to find 19².
  35. 35.Find the value of x² + 2xy + y² when x = 6 and y = 2.
  36. 36.Use (a − b)² = a² − 2ab + b² to find 34².
  37. 37.Use (a + b)² = a² + 2ab + b² to find 72².
  38. 38.Use (a − b)² = a² − 2ab + b² to find 83².
  39. 39.Use (a + b)(a − b) = a² − b² to find 75 × 65.
  40. 40.Use (a + b)(a − b) = a² − b² to find 89 × 71.

Answer key

  1. 9021
  2. 3969
  3. 5888
  4. 1065
  5. 8649
  6. 4480
  7. 6724
  8. 9
  9. 2419
  10. 1368
  11. 4356
  12. 1545
  13. 5776
  14. 2116
  15. 19
  16. 484
  17. 4761
  18. 82
  19. 6237
  20. 1
  21. 82
  22. 36
  23. 16
  24. 4
  25. 625
  26. 9025
  27. 265
  28. 1681
  29. 2576
  30. 25
  31. 1369
  32. 3844
  33. 117
  34. 361
  35. 64
  36. 1156
  37. 5184
  38. 6889
  39. 4875
  40. 6319

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