Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 163 · 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 = 2 and ab = 8, what is a² + b²?
2. 2.Use (a + b)(a − b) = a² − b² to find 86 × 74.
3. 3.Use a² − b² = (a + b)(a − b) to find 69² − 1².
4. 4.Use (a + b)² = a² + 2ab + b² to find 43².
5. 5.Use (a + b)(a − b) = a² − b² to find 92 × 88.
6. 6.Use (a + b)² = a² + 2ab + b² to find 86².
7. 7.Use (a − b)² = a² − 2ab + b² to find 82².
8. 8.Use (a − b)² = a² − 2ab + b² to find 11².
9. 9.Use (a − b)² = a² − 2ab + b² to find 61².
10. 10.Find the value of x² − y² when x = 3 and y = 1.
11. 11.Find the value of x² − y² when x = 4 and y = 1.
12. 12.Find the value of x² − 2xy + y² when x = 7 and y = 1.
13. 13.Use a² − b² = (a + b)(a − b) to find 31² − 15².
14. 14.Use (a + b)(a − b) = a² − b² to find 69 × 51.
15. 15.Use a² − b² = (a + b)(a − b) to find 73² − 10².
16. 16.Use (a + b)(a − b) = a² − b² to find 81 × 79.
17. 17.Use (a − b)² = a² − 2ab + b² to find 93².
18. 18.Use (a + b)(a − b) = a² − b² to find 65 × 55.
19. 19.Use (a + b)² = a² + 2ab + b² to find 23².
20. 20.Use (a + b)² = a² + 2ab + b² to find 25².
21. 21.Use (a + b)² = a² + 2ab + b² to find 37².
22. 22.Use (a + b)(a − b) = a² − b² to find 49 × 31.
23. 23.Use (a − b)² = a² − 2ab + b² to find 46².
24. 24.Use (a − b)² = a² − 2ab + b² to find 71².
25. 25.Use a² − b² = (a + b)(a − b) to find 77² − 65².
26. 26.If a + b = 7 and ab = 6, what is a² + b²?
27. 27.Find the value of x² − y² when x = 5 and y = 3.
28. 28.If a + b = 4 and ab = 3, what is a² + b²?
29. 29.Use (a − b)² = a² − 2ab + b² to find 41².
30. 30.Find the value of x² − 2xy + y² when x = 9 and y = 4.
31. 31.Use (a + b)(a − b) = a² − b² to find 71 × 69.
32. 32.Use a² − b² = (a + b)(a − b) to find 51² − 1².
33. 33.If a + b = 21 and ab = 110, what is a² + b²?
34. 34.Use (a − b)² = a² − 2ab + b² to find 62².
35. 35.Use (a − b)² = a² − 2ab + b² to find 57².
36. 36.Use (a − b)² = a² − 2ab + b² to find 19².
37. 37.If a + b = 16 and ab = 60, what is a² + b²?
38. 38.Use a² − b² = (a + b)(a − b) to find 28² − 4².
39. 39.If a + b = 9 and ab = 8, what is a² + b²?
40. 40.Use (a − b)² = a² − 2ab + b² to find 34².

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