Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 220 · 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.Use (a + b)² = a² + 2ab + b² to find 62².
2. 2.Use (a − b)² = a² − 2ab + b² to find 36².
3. 3.Use a² − b² = (a + b)(a − b) to find 87² − 22².
4. 4.If a − b = 2 and ab = 99, what is a² + b²?
5. 5.Use (a − b)² = a² − 2ab + b² to find 49².
6. 6.Use (a − b)² = a² − 2ab + b² to find 43².
7. 7.If a − b = 5 and ab = 66, what is a² + b²?
8. 8.Use (a + b)(a − b) = a² − b² to find 77 × 63.
9. 9.Use (a − b)² = a² − 2ab + b² to find 94².
10. 10.Use (a + b)² = a² + 2ab + b² to find 97².
11. 11.Use a² − b² = (a + b)(a − b) to find 25² − 23².
12. 12.Use a² − b² = (a + b)(a − b) to find 40² − 9².
13. 13.Use (a − b)² = a² − 2ab + b² to find 53².
14. 14.Use (a − b)² = a² − 2ab + b² to find 81².
15. 15.Use (a + b)² = a² + 2ab + b² to find 35².
16. 16.Use a² − b² = (a + b)(a − b) to find 86² − 39².
17. 17.Use (a + b)(a − b) = a² − b² to find 96 × 84.
18. 18.Use (a − b)² = a² − 2ab + b² to find 79².
19. 19.Use (a + b)(a − b) = a² − b² to find 76 × 64.
20. 20.Use (a + b)² = a² + 2ab + b² to find 64².
21. 21.Find the value of x² + 2xy + y² when x = 15 and y = 9.
22. 22.Find the value of x² + 2xy + y² when x = 6 and y = 2.
23. 23.If a − b = 10 and ab = 11, what is a² + b²?
24. 24.Use (a − b)² = a² − 2ab + b² to find 97².
25. 25.Use (a + b)² = a² + 2ab + b² to find 29².
26. 26.Use a² − b² = (a + b)(a − b) to find 76² − 55².
27. 27.Use (a − b)² = a² − 2ab + b² to find 78².
28. 28.If a + b = 3 and ab = 2, what is a² + b²?
29. 29.Use (a + b)(a − b) = a² − b² to find 58 × 42.
30. 30.Use (a − b)² = a² − 2ab + b² to find 69².
31. 31.If a − b = 1 and ab = 2, what is a² + b²?
32. 32.Use (a + b)² = a² + 2ab + b² to find 106².
33. 33.Use (a + b)² = a² + 2ab + b² to find 63².
34. 34.Use (a + b)² = a² + 2ab + b² to find 103².
35. 35.Find the value of x² − y² when x = 13 and y = 8.
36. 36.Use (a + b)(a − b) = a² − b² to find 21 × 19.
37. 37.Find the value of x² + 2xy + y² when x = 5 and y = 1.
38. 38.Use (a + b)(a − b) = a² − b² to find 49 × 31.
39. 39.Use (a − b)² = a² − 2ab + b² to find 66².
40. 40.Find the value of x² − y² when x = 4 and y = 2.

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