Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 623 · 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 − 2xy + y² when x = 15 and y = 5.
2. 2.Use (a + b)(a − b) = a² − b² to find 57 × 43.
3. 3.If a + b = 13 and ab = 36, what is a² + b²?
4. 4.Use (a − b)² = a² − 2ab + b² to find 16².
5. 5.Use (a − b)² = a² − 2ab + b² to find 66².
6. 6.Use (a + b)(a − b) = a² − b² to find 82 × 78.
7. 7.Use (a − b)² = a² − 2ab + b² to find 73².
8. 8.Find the value of x² − y² when x = 7 and y = 4.
9. 9.If a − b = 3 and ab = 10, what is a² + b²?
10. 10.Use (a − b)² = a² − 2ab + b² to find 24².
11. 11.Use a² − b² = (a + b)(a − b) to find 71² − 12².
12. 12.Find the value of x² − y² when x = 8 and y = 1.
13. 13.Use (a − b)² = a² − 2ab + b² to find 27².
14. 14.Use a² − b² = (a + b)(a − b) to find 62² − 21².
15. 15.Use (a − b)² = a² − 2ab + b² to find 49².
16. 16.Use (a − b)² = a² − 2ab + b² to find 86².
17. 17.Use (a − b)² = a² − 2ab + b² to find 39².
18. 18.Find the value of x² − 2xy + y² when x = 3 and y = 1.
19. 19.Use (a + b)(a − b) = a² − b² to find 69 × 51.
20. 20.If a − b = 5 and ab = 14, what is a² + b²?
21. 21.Use (a − b)² = a² − 2ab + b² to find 21².
22. 22.Use (a − b)² = a² − 2ab + b² to find 33².
23. 23.Use (a − b)² = a² − 2ab + b² to find 71².
24. 24.Use (a + b)² = a² + 2ab + b² to find 24².
25. 25.Use (a − b)² = a² − 2ab + b² to find 77².
26. 26.Use (a + b)² = a² + 2ab + b² to find 79².
27. 27.If a − b = 6 and ab = 40, what is a² + b²?
28. 28.Find the value of x² − 2xy + y² when x = 9 and y = 6.
29. 29.Use (a + b)² = a² + 2ab + b² to find 71².
30. 30.Use (a − b)² = a² − 2ab + b² to find 98².
31. 31.Use (a + b)² = a² + 2ab + b² to find 18².
32. 32.If a − b = 1 and ab = 12, what is a² + b²?
33. 33.Use (a − b)² = a² − 2ab + b² to find 36².
34. 34.Use a² − b² = (a + b)(a − b) to find 49² − 4².
35. 35.Use (a − b)² = a² − 2ab + b² to find 32².
36. 36.If a − b = 4 and ab = 12, what is a² + b²?
37. 37.Find the value of x² + 2xy + y² when x = 15 and y = 6.
38. 38.Use (a − b)² = a² − 2ab + b² to find 81².
39. 39.Use a² − b² = (a + b)(a − b) to find 95² − 46².
40. 40.Use a² − b² = (a + b)(a − b) to find 96² − 54².

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