← Algebraic identities lesson New set →

Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 939 · 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 − y² when x = 9 and y = 6.
  2. 2.Use (a − b)² = a² − 2ab + b² to find 19².
  3. 3.Find the value of x² − 2xy + y² when x = 10 and y = 4.
  4. 4.Use (a + b)(a − b) = a² − b² to find 87 × 73.
  5. 5.Use (a + b)² = a² + 2ab + b² to find 97².
  6. 6.Use (a + b)² = a² + 2ab + b² to find 33².
  7. 7.Use a² − b² = (a + b)(a − b) to find 84² − 54².
  8. 8.Use (a + b)² = a² + 2ab + b² to find 16².
  9. 9.Use (a + b)(a − b) = a² − b² to find 71 × 69.
  10. 10.Use (a + b)² = a² + 2ab + b² to find 37².
  11. 11.Use (a + b)² = a² + 2ab + b² to find 21².
  12. 12.Use (a + b)(a − b) = a² − b² to find 66 × 54.
  13. 13.Use (a − b)² = a² − 2ab + b² to find 59².
  14. 14.If a + b = 8 and ab = 15, what is a² + b²?
  15. 15.Use (a − b)² = a² − 2ab + b² to find 58².
  16. 16.Use (a − b)² = a² − 2ab + b² to find 69².
  17. 17.Use (a − b)² = a² − 2ab + b² to find 98².
  18. 18.Use (a + b)² = a² + 2ab + b² to find 105².
  19. 19.Use (a + b)(a − b) = a² − b² to find 88 × 72.
  20. 20.If a − b = 2 and ab = 3, what is a² + b²?
  21. 21.Find the value of x² − y² when x = 5 and y = 4.
  22. 22.Use (a + b)(a − b) = a² − b² to find 43 × 37.
  23. 23.Use (a − b)² = a² − 2ab + b² to find 81².
  24. 24.Use (a + b)(a − b) = a² − b² to find 108 × 92.
  25. 25.Use a² − b² = (a + b)(a − b) to find 89² − 44².
  26. 26.Find the value of x² − y² when x = 10 and y = 3.
  27. 27.If a − b = 6 and ab = 7, what is a² + b²?
  28. 28.Find the value of x² + 2xy + y² when x = 11 and y = 3.
  29. 29.Find the value of x² + 2xy + y² when x = 5 and y = 4.
  30. 30.Use (a + b)(a − b) = a² − b² to find 69 × 51.
  31. 31.Use (a + b)(a − b) = a² − b² to find 61 × 59.
  32. 32.Use (a + b)² = a² + 2ab + b² to find 46².
  33. 33.Use (a + b)(a − b) = a² − b² to find 82 × 78.
  34. 34.Use (a + b)(a − b) = a² − b² to find 109 × 91.
  35. 35.Use (a + b)² = a² + 2ab + b² to find 32².
  36. 36.If a − b = 4 and ab = 32, what is a² + b²?
  37. 37.Use (a + b)² = a² + 2ab + b² to find 69².
  38. 38.Use (a + b)² = a² + 2ab + b² to find 43².
  39. 39.Use a² − b² = (a + b)(a − b) to find 43² − 29².
  40. 40.Use (a − b)² = a² − 2ab + b² to find 13².

Answer key

  1. 45
  2. 361
  3. 36
  4. 6351
  5. 9409
  6. 1089
  7. 4140
  8. 256
  9. 4899
  10. 1369
  11. 441
  12. 3564
  13. 3481
  14. 34
  15. 3364
  16. 4761
  17. 9604
  18. 11025
  19. 6336
  20. 10
  21. 9
  22. 1591
  23. 6561
  24. 9936
  25. 5985
  26. 91
  27. 50
  28. 196
  29. 81
  30. 3519
  31. 3599
  32. 2116
  33. 6396
  34. 9919
  35. 1024
  36. 80
  37. 4761
  38. 1849
  39. 1008
  40. 169

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