← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 584 · 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 41² − 7².
  2. 2.Use (a + b)² = a² + 2ab + b² to find 47².
  3. 3.Find the value of x² − y² when x = 11 and y = 1.
  4. 4.Find the value of x² − 2xy + y² when x = 13 and y = 7.
  5. 5.Use (a − b)² = a² − 2ab + b² to find 68².
  6. 6.Use a² − b² = (a + b)(a − b) to find 20² − 15².
  7. 7.Find the value of x² − y² when x = 4 and y = 3.
  8. 8.Use a² − b² = (a + b)(a − b) to find 32² − 24².
  9. 9.Use (a + b)² = a² + 2ab + b² to find 95².
  10. 10.Use (a + b)(a − b) = a² − b² to find 64 × 56.
  11. 11.Find the value of x² + 2xy + y² when x = 12 and y = 2.
  12. 12.Use (a + b)² = a² + 2ab + b² to find 63².
  13. 13.If a − b = 5 and ab = 24, what is a² + b²?
  14. 14.Use (a + b)² = a² + 2ab + b² to find 42².
  15. 15.Use (a − b)² = a² − 2ab + b² to find 74².
  16. 16.Find the value of x² − 2xy + y² when x = 12 and y = 6.
  17. 17.Use (a + b)(a − b) = a² − b² to find 23 × 17.
  18. 18.Find the value of x² − y² when x = 8 and y = 1.
  19. 19.Use (a − b)² = a² − 2ab + b² to find 16².
  20. 20.Find the value of x² − y² when x = 10 and y = 6.
  21. 21.Find the value of x² + 2xy + y² when x = 3 and y = 2.
  22. 22.Use a² − b² = (a + b)(a − b) to find 38² − 29².
  23. 23.Use (a + b)(a − b) = a² − b² to find 25 × 15.
  24. 24.Use (a − b)² = a² − 2ab + b² to find 53².
  25. 25.Find the value of x² + 2xy + y² when x = 13 and y = 7.
  26. 26.Use (a + b)² = a² + 2ab + b² to find 88².
  27. 27.Use (a + b)² = a² + 2ab + b² to find 72².
  28. 28.Use (a − b)² = a² − 2ab + b² to find 35².
  29. 29.Find the value of x² − y² when x = 3 and y = 2.
  30. 30.Use a² − b² = (a + b)(a − b) to find 37² − 7².
  31. 31.Use (a + b)² = a² + 2ab + b² to find 15².
  32. 32.Use (a − b)² = a² − 2ab + b² to find 11².
  33. 33.Find the value of x² + 2xy + y² when x = 4 and y = 1.
  34. 34.Use (a + b)(a − b) = a² − b² to find 84 × 76.
  35. 35.Use a² − b² = (a + b)(a − b) to find 91² − 31².
  36. 36.Use (a + b)² = a² + 2ab + b² to find 85².
  37. 37.Use (a + b)² = a² + 2ab + b² to find 38².
  38. 38.Use (a + b)(a − b) = a² − b² to find 62 × 58.
  39. 39.If a − b = 1 and ab = 6, what is a² + b²?
  40. 40.Find the value of x² − y² when x = 15 and y = 11.

Answer key

  1. 1632
  2. 2209
  3. 120
  4. 36
  5. 4624
  6. 175
  7. 7
  8. 448
  9. 9025
  10. 3584
  11. 196
  12. 3969
  13. 73
  14. 1764
  15. 5476
  16. 36
  17. 391
  18. 63
  19. 256
  20. 64
  21. 25
  22. 603
  23. 375
  24. 2809
  25. 400
  26. 7744
  27. 5184
  28. 1225
  29. 5
  30. 1320
  31. 225
  32. 121
  33. 25
  34. 6384
  35. 7320
  36. 7225
  37. 1444
  38. 3596
  39. 13
  40. 104

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