Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 915 · 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 − 62².
2. 2.Use (a + b)² = a² + 2ab + b² to find 74².
3. 3.Use (a − b)² = a² − 2ab + b² to find 52².
4. 4.Use (a + b)² = a² + 2ab + b² to find 63².
5. 5.Use (a + b)² = a² + 2ab + b² to find 91².
6. 6.If a − b = 3 and ab = 70, what is a² + b²?
7. 7.Use (a + b)(a − b) = a² − b² to find 93 × 87.
8. 8.Use (a − b)² = a² − 2ab + b² to find 55².
9. 9.Use (a − b)² = a² − 2ab + b² to find 15².
10. 10.If a + b = 10 and ab = 16, what is a² + b²?
11. 11.Find the value of x² − 2xy + y² when x = 8 and y = 1.
12. 12.Use (a − b)² = a² − 2ab + b² to find 57².
13. 13.Use (a − b)² = a² − 2ab + b² to find 24².
14. 14.Find the value of x² + 2xy + y² when x = 3 and y = 1.
15. 15.If a + b = 14 and ab = 40, what is a² + b²?
16. 16.Use (a + b)² = a² + 2ab + b² to find 43².
17. 17.Use a² − b² = (a + b)(a − b) to find 25² − 2².
18. 18.Use (a + b)(a − b) = a² − b² to find 65 × 55.
19. 19.Use (a + b)² = a² + 2ab + b² to find 69².
20. 20.Use (a − b)² = a² − 2ab + b² to find 97².
21. 21.Use (a − b)² = a² − 2ab + b² to find 49².
22. 22.Use a² − b² = (a + b)(a − b) to find 39² − 15².
23. 23.Use (a + b)² = a² + 2ab + b² to find 15².
24. 24.Find the value of x² − y² when x = 13 and y = 4.
25. 25.Use (a + b)(a − b) = a² − b² to find 81 × 79.
26. 26.If a + b = 11 and ab = 10, what is a² + b²?
27. 27.Use (a + b)² = a² + 2ab + b² to find 68².
28. 28.If a + b = 21 and ab = 108, what is a² + b²?
29. 29.Use a² − b² = (a + b)(a − b) to find 72² − 34².
30. 30.Use (a + b)² = a² + 2ab + b² to find 59².
31. 31.Use (a + b)² = a² + 2ab + b² to find 94².
32. 32.If a + b = 3 and ab = 2, what is a² + b²?
33. 33.Use (a + b)(a − b) = a² − b² to find 31 × 29.
34. 34.If a − b = 1 and ab = 132, what is a² + b²?
35. 35.Use (a + b)² = a² + 2ab + b² to find 98².
36. 36.If a − b = 6 and ab = 7, what is a² + b²?
37. 37.Use a² − b² = (a + b)(a − b) to find 77² − 11².
38. 38.Use (a + b)² = a² + 2ab + b² to find 26².
39. 39.Find the value of x² + 2xy + y² when x = 4 and y = 1.
40. 40.If a − b = 6 and ab = 27, what is a² + b²?

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