Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 3 · 40 sums

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.

1. 1.Find the value of x² − y² when x = 8 and y = 3.
2. 2.Use (a + b)(a − b) = a² − b² to find 28 × 12.
3. 3.Use (a − b)² = a² − 2ab + b² to find 16².
4. 4.If a − b = 4 and ab = 12, what is a² + b²?
5. 5.If a + b = 5 and ab = 6, what is a² + b²?
6. 6.Use (a − b)² = a² − 2ab + b² to find 83².
7. 7.Use (a − b)² = a² − 2ab + b² to find 59².
8. 8.Use (a + b)(a − b) = a² − b² to find 84 × 76.
9. 9.Use (a + b)² = a² + 2ab + b² to find 12².
10. 10.Use a² − b² = (a + b)(a − b) to find 85² − 41².
11. 11.Use (a − b)² = a² − 2ab + b² to find 38².
12. 12.Use a² − b² = (a + b)(a − b) to find 28² − 9².
13. 13.Use a² − b² = (a + b)(a − b) to find 70² − 34².
14. 14.Use (a + b)(a − b) = a² − b² to find 63 × 57.
15. 15.Use a² − b² = (a + b)(a − b) to find 43² − 37².
16. 16.Use (a − b)² = a² − 2ab + b² to find 67².
17. 17.Use a² − b² = (a + b)(a − b) to find 98² − 69².
18. 18.Find the value of x² − 2xy + y² when x = 12 and y = 3.
19. 19.Use (a + b)(a − b) = a² − b² to find 93 × 87.
20. 20.Find the value of x² + 2xy + y² when x = 12 and y = 8.
21. 21.Use (a + b)² = a² + 2ab + b² to find 105².
22. 22.Use (a + b)(a − b) = a² − b² to find 69 × 51.
23. 23.If a + b = 17 and ab = 72, what is a² + b²?
24. 24.Use a² − b² = (a + b)(a − b) to find 55² − 36².
25. 25.Use a² − b² = (a + b)(a − b) to find 56² − 30².
26. 26.Use (a + b)² = a² + 2ab + b² to find 92².
27. 27.Use a² − b² = (a + b)(a − b) to find 34² − 18².
28. 28.Find the value of x² − y² when x = 6 and y = 5.
29. 29.Use (a + b)² = a² + 2ab + b² to find 39².
30. 30.Use a² − b² = (a + b)(a − b) to find 35² − 28².
31. 31.Find the value of x² − 2xy + y² when x = 12 and y = 6.
32. 32.Use (a + b)² = a² + 2ab + b² to find 22².
33. 33.Use (a + b)² = a² + 2ab + b² to find 17².
34. 34.Use (a + b)(a − b) = a² − b² to find 56 × 44.
35. 35.If a + b = 21 and ab = 110, what is a² + b²?
36. 36.Use (a + b)(a − b) = a² − b² to find 78 × 62.
37. 37.If a − b = 1 and ab = 12, what is a² + b²?
38. 38.Find the value of x² + 2xy + y² when x = 12 and y = 10.
39. 39.Use (a + b)² = a² + 2ab + b² to find 88².
40. 40.Use (a − b)² = a² − 2ab + b² to find 21².

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