← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 709 · 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)² = a² − 2ab + b² to find 84².
  2. 2.Use a² − b² = (a + b)(a − b) to find 68² − 53².
  3. 3.Use a² − b² = (a + b)(a − b) to find 56² − 12².
  4. 4.Use a² − b² = (a + b)(a − b) to find 64² − 1².
  5. 5.Use (a + b)² = a² + 2ab + b² to find 68².
  6. 6.Use (a + b)² = a² + 2ab + b² to find 86².
  7. 7.Use (a + b)² = a² + 2ab + b² to find 13².
  8. 8.Use a² − b² = (a + b)(a − b) to find 40² − 35².
  9. 9.Use (a + b)(a − b) = a² − b² to find 32 × 28.
  10. 10.Use (a + b)² = a² + 2ab + b² to find 103².
  11. 11.Use (a + b)² = a² + 2ab + b² to find 46².
  12. 12.Use a² − b² = (a + b)(a − b) to find 72² − 9².
  13. 13.Use (a + b)² = a² + 2ab + b² to find 41².
  14. 14.If a − b = 6 and ab = 55, what is a² + b²?
  15. 15.Use (a − b)² = a² − 2ab + b² to find 29².
  16. 16.If a + b = 6 and ab = 8, what is a² + b²?
  17. 17.Use (a − b)² = a² − 2ab + b² to find 31².
  18. 18.Find the value of x² + 2xy + y² when x = 7 and y = 1.
  19. 19.Use (a + b)(a − b) = a² − b² to find 69 × 51.
  20. 20.Use a² − b² = (a + b)(a − b) to find 59² − 19².
  21. 21.Find the value of x² − 2xy + y² when x = 11 and y = 8.
  22. 22.Use (a − b)² = a² − 2ab + b² to find 61².
  23. 23.Use (a + b)(a − b) = a² − b² to find 28 × 12.
  24. 24.If a + b = 6 and ab = 5, what is a² + b²?
  25. 25.Find the value of x² − y² when x = 12 and y = 8.
  26. 26.Find the value of x² − y² when x = 9 and y = 5.
  27. 27.If a − b = 4 and ab = 5, what is a² + b²?
  28. 28.Use (a − b)² = a² − 2ab + b² to find 65².
  29. 29.Use a² − b² = (a + b)(a − b) to find 64² − 12².
  30. 30.Use (a − b)² = a² − 2ab + b² to find 96².
  31. 31.If a + b = 3 and ab = 2, what is a² + b²?
  32. 32.Find the value of x² + 2xy + y² when x = 7 and y = 6.
  33. 33.Find the value of x² + 2xy + y² when x = 4 and y = 2.
  34. 34.Use (a − b)² = a² − 2ab + b² to find 66².
  35. 35.Use a² − b² = (a + b)(a − b) to find 47² − 45².
  36. 36.If a − b = 5 and ab = 6, what is a² + b²?
  37. 37.Use a² − b² = (a + b)(a − b) to find 65² − 28².
  38. 38.Use a² − b² = (a + b)(a − b) to find 67² − 53².
  39. 39.Use (a + b)² = a² + 2ab + b² to find 82².
  40. 40.If a + b = 11 and ab = 30, what is a² + b²?

Answer key

  1. 7056
  2. 1815
  3. 2992
  4. 4095
  5. 4624
  6. 7396
  7. 169
  8. 375
  9. 896
  10. 10609
  11. 2116
  12. 5103
  13. 1681
  14. 146
  15. 841
  16. 20
  17. 961
  18. 64
  19. 3519
  20. 3120
  21. 9
  22. 3721
  23. 336
  24. 26
  25. 80
  26. 56
  27. 26
  28. 4225
  29. 3952
  30. 9216
  31. 5
  32. 169
  33. 36
  34. 4356
  35. 184
  36. 37
  37. 3441
  38. 1680
  39. 6724
  40. 61

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