← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 193 · 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)(a − b) = a² − b² to find 108 × 92.
  2. 2.If a + b = 14 and ab = 40, what is a² + b²?
  3. 3.Use (a − b)² = a² − 2ab + b² to find 89².
  4. 4.If a + b = 6 and ab = 8, what is a² + b²?
  5. 5.Use (a + b)² = a² + 2ab + b² to find 15².
  6. 6.Use (a − b)² = a² − 2ab + b² to find 71².
  7. 7.Use (a + b)(a − b) = a² − b² to find 38 × 22.
  8. 8.Use (a + b)² = a² + 2ab + b² to find 32².
  9. 9.If a − b = 2 and ab = 48, what is a² + b²?
  10. 10.Find the value of x² − 2xy + y² when x = 13 and y = 8.
  11. 11.If a − b = 1 and ab = 2, what is a² + b²?
  12. 12.Use (a + b)(a − b) = a² − b² to find 48 × 32.
  13. 13.Find the value of x² − 2xy + y² when x = 4 and y = 3.
  14. 14.If a + b = 7 and ab = 12, what is a² + b²?
  15. 15.Find the value of x² − y² when x = 12 and y = 8.
  16. 16.Use (a + b)² = a² + 2ab + b² to find 73².
  17. 17.Use a² − b² = (a + b)(a − b) to find 63² − 35².
  18. 18.If a + b = 3 and ab = 2, what is a² + b²?
  19. 19.Use (a + b)² = a² + 2ab + b² to find 23².
  20. 20.Use (a − b)² = a² − 2ab + b² to find 27².
  21. 21.Use (a + b)² = a² + 2ab + b² to find 55².
  22. 22.Use a² − b² = (a + b)(a − b) to find 24² − 5².
  23. 23.Find the value of x² + 2xy + y² when x = 11 and y = 3.
  24. 24.Use (a + b)² = a² + 2ab + b² to find 24².
  25. 25.Use (a + b)² = a² + 2ab + b² to find 69².
  26. 26.Use (a − b)² = a² − 2ab + b² to find 87².
  27. 27.Use (a + b)(a − b) = a² − b² to find 91 × 89.
  28. 28.Use (a + b)² = a² + 2ab + b² to find 47².
  29. 29.Use a² − b² = (a + b)(a − b) to find 60² − 48².
  30. 30.Use (a + b)(a − b) = a² − b² to find 67 × 53.
  31. 31.Use a² − b² = (a + b)(a − b) to find 45² − 11².
  32. 32.Use (a − b)² = a² − 2ab + b² to find 61².
  33. 33.Use (a + b)² = a² + 2ab + b² to find 109².
  34. 34.Use (a − b)² = a² − 2ab + b² to find 93².
  35. 35.If a + b = 17 and ab = 70, what is a² + b²?
  36. 36.Use (a + b)² = a² + 2ab + b² to find 75².
  37. 37.Use (a + b)² = a² + 2ab + b² to find 51².
  38. 38.Use a² − b² = (a + b)(a − b) to find 52² − 3².
  39. 39.Use (a − b)² = a² − 2ab + b² to find 97².
  40. 40.Use (a − b)² = a² − 2ab + b² to find 33².

Answer key

  1. 9936
  2. 116
  3. 7921
  4. 20
  5. 225
  6. 5041
  7. 836
  8. 1024
  9. 100
  10. 25
  11. 5
  12. 1536
  13. 1
  14. 25
  15. 80
  16. 5329
  17. 2744
  18. 5
  19. 529
  20. 729
  21. 3025
  22. 551
  23. 196
  24. 576
  25. 4761
  26. 7569
  27. 8099
  28. 2209
  29. 1296
  30. 3551
  31. 1904
  32. 3721
  33. 11881
  34. 8649
  35. 149
  36. 5625
  37. 2601
  38. 2695
  39. 9409
  40. 1089

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