← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 950 · 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 48 × 32.
  2. 2.Use (a + b)(a − b) = a² − b² to find 37 × 23.
  3. 3.Use (a + b)² = a² + 2ab + b² to find 12².
  4. 4.Use (a + b)(a − b) = a² − b² to find 28 × 12.
  5. 5.Find the value of x² − 2xy + y² when x = 3 and y = 1.
  6. 6.Use (a − b)² = a² − 2ab + b² to find 55².
  7. 7.Find the value of x² + 2xy + y² when x = 9 and y = 1.
  8. 8.Use (a + b)² = a² + 2ab + b² to find 19².
  9. 9.Use (a + b)² = a² + 2ab + b² to find 97².
  10. 10.Find the value of x² − 2xy + y² when x = 13 and y = 1.
  11. 11.Use (a + b)² = a² + 2ab + b² to find 83².
  12. 12.Use a² − b² = (a + b)(a − b) to find 84² − 45².
  13. 13.Find the value of x² − y² when x = 8 and y = 4.
  14. 14.Use (a + b)(a − b) = a² − b² to find 42 × 38.
  15. 15.Use (a − b)² = a² − 2ab + b² to find 49².
  16. 16.Use (a − b)² = a² − 2ab + b² to find 29².
  17. 17.Use (a − b)² = a² − 2ab + b² to find 79².
  18. 18.Use (a + b)² = a² + 2ab + b² to find 89².
  19. 19.Use a² − b² = (a + b)(a − b) to find 34² − 16².
  20. 20.If a − b = 2 and ab = 35, what is a² + b²?
  21. 21.Use a² − b² = (a + b)(a − b) to find 56² − 7².
  22. 22.If a + b = 7 and ab = 12, what is a² + b²?
  23. 23.If a + b = 3 and ab = 2, what is a² + b²?
  24. 24.Use (a + b)² = a² + 2ab + b² to find 43².
  25. 25.Use (a − b)² = a² − 2ab + b² to find 91².
  26. 26.Use (a + b)(a − b) = a² − b² to find 53 × 47.
  27. 27.If a − b = 8 and ab = 20, what is a² + b²?
  28. 28.Find the value of x² − 2xy + y² when x = 4 and y = 3.
  29. 29.Use a² − b² = (a + b)(a − b) to find 78² − 38².
  30. 30.Use (a + b)(a − b) = a² − b² to find 82 × 78.
  31. 31.If a − b = 1 and ab = 2, what is a² + b²?
  32. 32.If a − b = 2 and ab = 8, what is a² + b²?
  33. 33.Use (a − b)² = a² − 2ab + b² to find 19².
  34. 34.Use a² − b² = (a + b)(a − b) to find 26² − 5².
  35. 35.Use (a + b)(a − b) = a² − b² to find 64 × 56.
  36. 36.Find the value of x² − 2xy + y² when x = 10 and y = 4.
  37. 37.Find the value of x² − y² when x = 10 and y = 4.
  38. 38.Use a² − b² = (a + b)(a − b) to find 32² − 22².
  39. 39.Use (a + b)² = a² + 2ab + b² to find 53².
  40. 40.If a − b = 6 and ab = 40, what is a² + b²?

Answer key

  1. 1536
  2. 851
  3. 144
  4. 336
  5. 4
  6. 3025
  7. 100
  8. 361
  9. 9409
  10. 144
  11. 6889
  12. 5031
  13. 48
  14. 1596
  15. 2401
  16. 841
  17. 6241
  18. 7921
  19. 900
  20. 74
  21. 3087
  22. 25
  23. 5
  24. 1849
  25. 8281
  26. 2491
  27. 104
  28. 1
  29. 4640
  30. 6396
  31. 5
  32. 20
  33. 361
  34. 651
  35. 3584
  36. 36
  37. 84
  38. 540
  39. 2809
  40. 116

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