← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 358 · 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.Find the value of x² − 2xy + y² when x = 3 and y = 2.
  2. 2.Find the value of x² − 2xy + y² when x = 6 and y = 2.
  3. 3.If a − b = 1 and ab = 2, what is a² + b²?
  4. 4.Use (a − b)² = a² − 2ab + b² to find 67².
  5. 5.If a + b = 9 and ab = 8, what is a² + b²?
  6. 6.Find the value of x² − 2xy + y² when x = 5 and y = 3.
  7. 7.Use a² − b² = (a + b)(a − b) to find 78² − 39².
  8. 8.Find the value of x² + 2xy + y² when x = 5 and y = 2.
  9. 9.If a + b = 12 and ab = 32, what is a² + b²?
  10. 10.Find the value of x² + 2xy + y² when x = 14 and y = 10.
  11. 11.Use (a + b)(a − b) = a² − b² to find 43 × 37.
  12. 12.If a + b = 14 and ab = 33, what is a² + b²?
  13. 13.Use (a + b)² = a² + 2ab + b² to find 78².
  14. 14.If a − b = 2 and ab = 24, what is a² + b²?
  15. 15.Use a² − b² = (a + b)(a − b) to find 22² − 12².
  16. 16.Find the value of x² − y² when x = 15 and y = 4.
  17. 17.Use (a + b)(a − b) = a² − b² to find 68 × 52.
  18. 18.If a − b = 1 and ab = 12, what is a² + b²?
  19. 19.If a − b = 3 and ab = 108, what is a² + b²?
  20. 20.Use (a + b)(a − b) = a² − b² to find 93 × 87.
  21. 21.If a − b = 1 and ab = 110, what is a² + b²?
  22. 22.Find the value of x² + 2xy + y² when x = 11 and y = 3.
  23. 23.If a + b = 3 and ab = 2, what is a² + b²?
  24. 24.Use (a + b)(a − b) = a² − b² to find 92 × 88.
  25. 25.Use (a + b)² = a² + 2ab + b² to find 81².
  26. 26.Find the value of x² + 2xy + y² when x = 3 and y = 2.
  27. 27.Use (a − b)² = a² − 2ab + b² to find 52².
  28. 28.Use (a + b)² = a² + 2ab + b² to find 48².
  29. 29.Use (a + b)(a − b) = a² − b² to find 39 × 21.
  30. 30.Use (a − b)² = a² − 2ab + b² to find 58².
  31. 31.Use a² − b² = (a + b)(a − b) to find 24² − 17².
  32. 32.Use (a − b)² = a² − 2ab + b² to find 18².
  33. 33.Use (a − b)² = a² − 2ab + b² to find 45².
  34. 34.Find the value of x² + 2xy + y² when x = 4 and y = 3.
  35. 35.Use (a − b)² = a² − 2ab + b² to find 38².
  36. 36.Use (a + b)(a − b) = a² − b² to find 104 × 96.
  37. 37.Use (a + b)² = a² + 2ab + b² to find 21².
  38. 38.If a − b = 2 and ab = 3, what is a² + b²?
  39. 39.Find the value of x² − 2xy + y² when x = 10 and y = 4.
  40. 40.Use a² − b² = (a + b)(a − b) to find 35² − 15².

Answer key

  1. 1
  2. 16
  3. 5
  4. 4489
  5. 65
  6. 4
  7. 4563
  8. 49
  9. 80
  10. 576
  11. 1591
  12. 130
  13. 6084
  14. 52
  15. 340
  16. 209
  17. 3536
  18. 25
  19. 225
  20. 8091
  21. 221
  22. 196
  23. 5
  24. 8096
  25. 6561
  26. 25
  27. 2704
  28. 2304
  29. 819
  30. 3364
  31. 287
  32. 324
  33. 2025
  34. 49
  35. 1444
  36. 9984
  37. 441
  38. 10
  39. 36
  40. 1000

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