← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 657 · 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 = 10, what is a² + b²?
  2. 2.Use (a − b)² = a² − 2ab + b² to find 59².
  3. 3.If a + b = 9 and ab = 18, what is a² + b²?
  4. 4.Use (a + b)(a − b) = a² − b² to find 34 × 26.
  5. 5.If a − b = 1 and ab = 2, what is a² + b²?
  6. 6.Use (a + b)² = a² + 2ab + b² to find 62².
  7. 7.Find the value of x² − 2xy + y² when x = 6 and y = 3.
  8. 8.Use (a + b)(a − b) = a² − b² to find 84 × 76.
  9. 9.Find the value of x² − y² when x = 5 and y = 2.
  10. 10.If a + b = 17 and ab = 72, what is a² + b²?
  11. 11.Find the value of x² − y² when x = 6 and y = 3.
  12. 12.Find the value of x² + 2xy + y² when x = 3 and y = 1.
  13. 13.Use a² − b² = (a + b)(a − b) to find 42² − 17².
  14. 14.Use (a − b)² = a² − 2ab + b² to find 77².
  15. 15.Use (a − b)² = a² − 2ab + b² to find 85².
  16. 16.If a + b = 13 and ab = 36, what is a² + b²?
  17. 17.Use (a + b)² = a² + 2ab + b² to find 49².
  18. 18.Use (a − b)² = a² − 2ab + b² to find 46².
  19. 19.If a − b = 1 and ab = 30, what is a² + b²?
  20. 20.Use (a − b)² = a² − 2ab + b² to find 11².
  21. 21.Use (a + b)² = a² + 2ab + b² to find 84².
  22. 22.Use (a + b)² = a² + 2ab + b² to find 77².
  23. 23.Use (a − b)² = a² − 2ab + b² to find 14².
  24. 24.Use a² − b² = (a + b)(a − b) to find 52² − 37².
  25. 25.Use (a − b)² = a² − 2ab + b² to find 21².
  26. 26.If a − b = 6 and ab = 55, what is a² + b²?
  27. 27.Use a² − b² = (a + b)(a − b) to find 29² − 12².
  28. 28.Find the value of x² + 2xy + y² when x = 11 and y = 6.
  29. 29.Use (a + b)² = a² + 2ab + b² to find 48².
  30. 30.Use (a + b)(a − b) = a² − b² to find 101 × 99.
  31. 31.Use (a + b)(a − b) = a² − b² to find 35 × 25.
  32. 32.Use (a − b)² = a² − 2ab + b² to find 28².
  33. 33.Use a² − b² = (a + b)(a − b) to find 23² − 2².
  34. 34.If a − b = 3 and ab = 28, what is a² + b²?
  35. 35.Use (a + b)(a − b) = a² − b² to find 66 × 54.
  36. 36.Use a² − b² = (a + b)(a − b) to find 29² − 27².
  37. 37.Use a² − b² = (a + b)(a − b) to find 47² − 33².
  38. 38.Find the value of x² − 2xy + y² when x = 11 and y = 9.
  39. 39.Use a² − b² = (a + b)(a − b) to find 89² − 74².
  40. 40.Use (a + b)² = a² + 2ab + b² to find 13².

Answer key

  1. 29
  2. 3481
  3. 45
  4. 884
  5. 5
  6. 3844
  7. 9
  8. 6384
  9. 21
  10. 145
  11. 27
  12. 16
  13. 1475
  14. 5929
  15. 7225
  16. 97
  17. 2401
  18. 2116
  19. 61
  20. 121
  21. 7056
  22. 5929
  23. 196
  24. 1335
  25. 441
  26. 146
  27. 697
  28. 289
  29. 2304
  30. 9999
  31. 875
  32. 784
  33. 525
  34. 65
  35. 3564
  36. 112
  37. 1120
  38. 4
  39. 2445
  40. 169

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