← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 13 · 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.If a − b = 7 and ab = 60, what is a² + b²?
  2. 2.Use (a + b)² = a² + 2ab + b² to find 104².
  3. 3.Use (a − b)² = a² − 2ab + b² to find 51².
  4. 4.Use a² − b² = (a + b)(a − b) to find 36² − 18².
  5. 5.Use (a + b)² = a² + 2ab + b² to find 29².
  6. 6.Use (a + b)(a − b) = a² − b² to find 47 × 33.
  7. 7.If a + b = 8 and ab = 15, what is a² + b²?
  8. 8.If a + b = 3 and ab = 2, what is a² + b²?
  9. 9.If a + b = 4 and ab = 3, what is a² + b²?
  10. 10.Use (a + b)(a − b) = a² − b² to find 66 × 54.
  11. 11.Find the value of x² + 2xy + y² when x = 15 and y = 4.
  12. 12.Use (a − b)² = a² − 2ab + b² to find 79².
  13. 13.Find the value of x² − y² when x = 14 and y = 13.
  14. 14.Use (a − b)² = a² − 2ab + b² to find 86².
  15. 15.Use (a − b)² = a² − 2ab + b² to find 19².
  16. 16.Use a² − b² = (a + b)(a − b) to find 39² − 1².
  17. 17.Use (a + b)² = a² + 2ab + b² to find 102².
  18. 18.Find the value of x² + 2xy + y² when x = 7 and y = 1.
  19. 19.Find the value of x² − y² when x = 3 and y = 2.
  20. 20.If a + b = 8 and ab = 12, what is a² + b²?
  21. 21.Use (a + b)(a − b) = a² − b² to find 73 × 67.
  22. 22.Use (a + b)² = a² + 2ab + b² to find 61².
  23. 23.If a − b = 2 and ab = 3, what is a² + b²?
  24. 24.Use (a + b)² = a² + 2ab + b² to find 95².
  25. 25.If a − b = 6 and ab = 16, what is a² + b²?
  26. 26.Find the value of x² − y² when x = 8 and y = 7.
  27. 27.Use (a − b)² = a² − 2ab + b² to find 52².
  28. 28.Use (a + b)(a − b) = a² − b² to find 57 × 43.
  29. 29.Use (a − b)² = a² − 2ab + b² to find 64².
  30. 30.Use (a − b)² = a² − 2ab + b² to find 14².
  31. 31.If a + b = 22 and ab = 120, what is a² + b²?
  32. 32.Find the value of x² + 2xy + y² when x = 6 and y = 5.
  33. 33.Use (a + b)(a − b) = a² − b² to find 68 × 52.
  34. 34.Use (a − b)² = a² − 2ab + b² to find 32².
  35. 35.Find the value of x² + 2xy + y² when x = 3 and y = 2.
  36. 36.Use (a + b)² = a² + 2ab + b² to find 31².
  37. 37.Use (a + b)(a − b) = a² − b² to find 95 × 85.
  38. 38.Use (a − b)² = a² − 2ab + b² to find 31².
  39. 39.Use a² − b² = (a + b)(a − b) to find 66² − 6².
  40. 40.Find the value of x² − 2xy + y² when x = 12 and y = 4.

Answer key

  1. 169
  2. 10816
  3. 2601
  4. 972
  5. 841
  6. 1551
  7. 34
  8. 5
  9. 10
  10. 3564
  11. 361
  12. 6241
  13. 27
  14. 7396
  15. 361
  16. 1520
  17. 10404
  18. 64
  19. 5
  20. 40
  21. 4891
  22. 3721
  23. 10
  24. 9025
  25. 68
  26. 15
  27. 2704
  28. 2451
  29. 4096
  30. 196
  31. 244
  32. 121
  33. 3536
  34. 1024
  35. 25
  36. 961
  37. 8075
  38. 961
  39. 4320
  40. 64

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