Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 76 · 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 85² − 8².
2. 2.If a − b = 4 and ab = 5, what is a² + b²?
3. 3.Use (a + b)(a − b) = a² − b² to find 65 × 55.
4. 4.If a + b = 5 and ab = 6, what is a² + b²?
5. 5.Use (a + b)² = a² + 2ab + b² to find 19².
6. 6.Find the value of x² + 2xy + y² when x = 3 and y = 2.
7. 7.Use (a + b)² = a² + 2ab + b² to find 38².
8. 8.Use a² − b² = (a + b)(a − b) to find 50² − 39².
9. 9.Use a² − b² = (a + b)(a − b) to find 45² − 30².
10. 10.Use (a + b)(a − b) = a² − b² to find 53 × 47.
11. 11.If a + b = 11 and ab = 10, what is a² + b²?
12. 12.Use (a + b)² = a² + 2ab + b² to find 66².
13. 13.Use (a + b)² = a² + 2ab + b² to find 28².
14. 14.Use a² − b² = (a + b)(a − b) to find 24² − 17².
15. 15.Use (a − b)² = a² − 2ab + b² to find 37².
16. 16.If a − b = 6 and ab = 27, what is a² + b²?
17. 17.Use (a + b)² = a² + 2ab + b² to find 92².
18. 18.If a − b = 1 and ab = 12, what is a² + b²?
19. 19.Find the value of x² − y² when x = 8 and y = 2.
20. 20.If a − b = 2 and ab = 15, what is a² + b²?
21. 21.Use (a + b)(a − b) = a² − b² to find 27 × 13.
22. 22.Use (a + b)² = a² + 2ab + b² to find 89².
23. 23.Use (a + b)² = a² + 2ab + b² to find 88².
24. 24.Use a² − b² = (a + b)(a − b) to find 56² − 28².
25. 25.Use (a + b)(a − b) = a² − b² to find 79 × 61.
26. 26.Use (a + b)(a − b) = a² − b² to find 83 × 77.
27. 27.Use (a + b)(a − b) = a² − b² to find 71 × 69.
28. 28.Use (a + b)(a − b) = a² − b² to find 93 × 87.
29. 29.Use (a + b)(a − b) = a² − b² to find 55 × 45.
30. 30.Use (a + b)(a − b) = a² − b² to find 101 × 99.
31. 31.Use (a + b)(a − b) = a² − b² to find 32 × 28.
32. 32.Use (a − b)² = a² − 2ab + b² to find 96².
33. 33.Use (a − b)² = a² − 2ab + b² to find 92².
34. 34.If a − b = 1 and ab = 72, what is a² + b²?
35. 35.Use (a − b)² = a² − 2ab + b² to find 38².
36. 36.If a − b = 7 and ab = 60, what is a² + b²?
37. 37.Use (a − b)² = a² − 2ab + b² to find 69².
38. 38.Use (a + b)² = a² + 2ab + b² to find 44².
39. 39.If a + b = 15 and ab = 44, what is a² + b²?
40. 40.Use a² − b² = (a + b)(a − b) to find 99² − 41².

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