Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 99 · 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 a² − b² = (a + b)(a − b) to find 39² − 22².
2. 2.Use (a − b)² = a² − 2ab + b² to find 49².
3. 3.Use a² − b² = (a + b)(a − b) to find 53² − 12².
4. 4.Use a² − b² = (a + b)(a − b) to find 51² − 10².
5. 5.Use (a − b)² = a² − 2ab + b² to find 71².
6. 6.Find the value of x² − y² when x = 13 and y = 2.
7. 7.Use a² − b² = (a + b)(a − b) to find 33² − 28².
8. 8.Use a² − b² = (a + b)(a − b) to find 61² − 6².
9. 9.Find the value of x² − 2xy + y² when x = 13 and y = 10.
10. 10.Use (a + b)(a − b) = a² − b² to find 28 × 12.
11. 11.Use (a + b)² = a² + 2ab + b² to find 65².
12. 12.Use (a + b)(a − b) = a² − b² to find 21 × 19.
13. 13.Use (a − b)² = a² − 2ab + b² to find 13².
14. 14.Use a² − b² = (a + b)(a − b) to find 78² − 19².
15. 15.Find the value of x² + 2xy + y² when x = 3 and y = 2.
16. 16.Use a² − b² = (a + b)(a − b) to find 37² − 27².
17. 17.Use a² − b² = (a + b)(a − b) to find 28² − 9².
18. 18.Use (a + b)(a − b) = a² − b² to find 62 × 58.
19. 19.Use (a + b)(a − b) = a² − b² to find 34 × 26.
20. 20.Use a² − b² = (a + b)(a − b) to find 66² − 60².
21. 21.Find the value of x² + 2xy + y² when x = 9 and y = 4.
22. 22.Use (a + b)(a − b) = a² − b² to find 69 × 51.
23. 23.If a − b = 6 and ab = 16, what is a² + b²?
24. 24.Use (a + b)² = a² + 2ab + b² to find 23².
25. 25.Use (a − b)² = a² − 2ab + b² to find 35².
26. 26.If a + b = 7 and ab = 12, what is a² + b²?
27. 27.Use (a + b)(a − b) = a² − b² to find 52 × 48.
28. 28.Use a² − b² = (a + b)(a − b) to find 23² − 14².
29. 29.If a + b = 7 and ab = 6, what is a² + b²?
30. 30.If a + b = 7 and ab = 10, what is a² + b²?
31. 31.Use (a − b)² = a² − 2ab + b² to find 39².
32. 32.Use (a + b)(a − b) = a² − b² to find 108 × 92.
33. 33.Use (a − b)² = a² − 2ab + b² to find 83².
34. 34.Use (a − b)² = a² − 2ab + b² to find 69².
35. 35.Use (a + b)² = a² + 2ab + b² to find 74².
36. 36.Use a² − b² = (a + b)(a − b) to find 49² − 7².
37. 37.If a − b = 8 and ab = 9, what is a² + b²?
38. 38.Use (a + b)(a − b) = a² − b² to find 56 × 44.
39. 39.Use (a − b)² = a² − 2ab + b² to find 67².
40. 40.If a − b = 9 and ab = 10, what is a² + b²?

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