Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 215 · 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 = 20 and ab = 96, what is a² + b²?
2. 2.Use (a + b)(a − b) = a² − b² to find 62 × 58.
3. 3.Use (a − b)² = a² − 2ab + b² to find 13².
4. 4.If a + b = 11 and ab = 28, what is a² + b²?
5. 5.Use a² − b² = (a + b)(a − b) to find 27² − 26².
6. 6.If a + b = 9 and ab = 20, what is a² + b²?
7. 7.Use (a + b)² = a² + 2ab + b² to find 61².
8. 8.Use (a − b)² = a² − 2ab + b² to find 15².
9. 9.Find the value of x² − 2xy + y² when x = 15 and y = 5.
10. 10.Use (a + b)² = a² + 2ab + b² to find 96².
11. 11.Use (a − b)² = a² − 2ab + b² to find 28².
12. 12.Use (a + b)² = a² + 2ab + b² to find 97².
13. 13.Use (a − b)² = a² − 2ab + b² to find 91².
14. 14.Use (a + b)(a − b) = a² − b² to find 75 × 65.
15. 15.Use a² − b² = (a + b)(a − b) to find 43² − 38².
16. 16.Use a² − b² = (a + b)(a − b) to find 28² − 22².
17. 17.Use (a + b)² = a² + 2ab + b² to find 33².
18. 18.Use (a − b)² = a² − 2ab + b² to find 11².
19. 19.Use (a − b)² = a² − 2ab + b² to find 43².
20. 20.Use (a − b)² = a² − 2ab + b² to find 66².
21. 21.Use (a + b)(a − b) = a² − b² to find 67 × 53.
22. 22.Use (a − b)² = a² − 2ab + b² to find 98².
23. 23.If a − b = 10 and ab = 24, what is a² + b²?
24. 24.Use (a + b)(a − b) = a² − b² to find 54 × 46.
25. 25.Use a² − b² = (a + b)(a − b) to find 42² − 30².
26. 26.Use (a + b)(a − b) = a² − b² to find 33 × 27.
27. 27.Use (a + b)² = a² + 2ab + b² to find 66².
28. 28.Use (a + b)² = a² + 2ab + b² to find 103².
29. 29.Use (a − b)² = a² − 2ab + b² to find 41².
30. 30.Use (a + b)² = a² + 2ab + b² to find 37².
31. 31.Find the value of x² + 2xy + y² when x = 14 and y = 1.
32. 32.Use a² − b² = (a + b)(a − b) to find 73² − 9².
33. 33.Use (a + b)(a − b) = a² − b² to find 27 × 13.
34. 34.Find the value of x² + 2xy + y² when x = 15 and y = 2.
35. 35.Use a² − b² = (a + b)(a − b) to find 96² − 27².
36. 36.Use a² − b² = (a + b)(a − b) to find 79² − 56².
37. 37.Use a² − b² = (a + b)(a − b) to find 56² − 12².
38. 38.Use a² − b² = (a + b)(a − b) to find 36² − 25².
39. 39.Use (a − b)² = a² − 2ab + b² to find 37².
40. 40.Use (a + b)(a − b) = a² − b² to find 22 × 18.

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