Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 791 · 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.If a + b = 3 and ab = 2, what is a² + b²?
2. 2.Use a² − b² = (a + b)(a − b) to find 24² − 19².
3. 3.If a − b = 1 and ab = 12, what is a² + b²?
4. 4.If a − b = 6 and ab = 16, what is a² + b²?
5. 5.Use (a − b)² = a² − 2ab + b² to find 27².
6. 6.Use (a + b)² = a² + 2ab + b² to find 43².
7. 7.Use (a + b)² = a² + 2ab + b² to find 62².
8. 8.If a − b = 1 and ab = 6, what is a² + b²?
9. 9.Use (a + b)(a − b) = a² − b² to find 101 × 99.
10. 10.Use (a + b)(a − b) = a² − b² to find 46 × 34.
11. 11.Use (a − b)² = a² − 2ab + b² to find 81².
12. 12.If a − b = 10 and ab = 24, what is a² + b²?
13. 13.If a − b = 6 and ab = 40, what is a² + b²?
14. 14.Use a² − b² = (a + b)(a − b) to find 60² − 11².
15. 15.Use (a + b)² = a² + 2ab + b² to find 103².
16. 16.Use (a − b)² = a² − 2ab + b² to find 69².
17. 17.Use (a − b)² = a² − 2ab + b² to find 51².
18. 18.If a + b = 18 and ab = 72, what is a² + b²?
19. 19.Use (a + b)² = a² + 2ab + b² to find 73².
20. 20.Use (a + b)² = a² + 2ab + b² to find 71².
21. 21.Use a² − b² = (a + b)(a − b) to find 74² − 66².
22. 22.Use (a − b)² = a² − 2ab + b² to find 24².
23. 23.Use a² − b² = (a + b)(a − b) to find 25² − 17².
24. 24.Use (a + b)² = a² + 2ab + b² to find 31².
25. 25.Use (a + b)(a − b) = a² − b² to find 98 × 82.
26. 26.If a − b = 2 and ab = 35, what is a² + b²?
27. 27.Use (a − b)² = a² − 2ab + b² to find 91².
28. 28.Find the value of x² + 2xy + y² when x = 4 and y = 3.
29. 29.Use a² − b² = (a + b)(a − b) to find 22² − 15².
30. 30.Find the value of x² − y² when x = 12 and y = 5.
31. 31.Use a² − b² = (a + b)(a − b) to find 73² − 2².
32. 32.Use (a + b)² = a² + 2ab + b² to find 66².
33. 33.Use (a + b)² = a² + 2ab + b² to find 16².
34. 34.Use (a − b)² = a² − 2ab + b² to find 93².
35. 35.Find the value of x² + 2xy + y² when x = 8 and y = 1.
36. 36.If a − b = 8 and ab = 20, what is a² + b²?
37. 37.If a + b = 11 and ab = 10, what is a² + b²?
38. 38.Use (a − b)² = a² − 2ab + b² to find 53².
39. 39.Find the value of x² + 2xy + y² when x = 13 and y = 10.
40. 40.Use (a + b)(a − b) = a² − b² to find 38 × 22.

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