Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 635 · 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 = 120, what is a² + b²?
2. 2.Use (a + b)² = a² + 2ab + b² to find 61².
3. 3.Use (a + b)(a − b) = a² − b² to find 36 × 24.
4. 4.Use a² − b² = (a + b)(a − b) to find 46² − 43².
5. 5.Find the value of x² − 2xy + y² when x = 7 and y = 5.
6. 6.If a + b = 16 and ab = 63, what is a² + b²?
7. 7.If a − b = 9 and ab = 22, what is a² + b²?
8. 8.Use (a − b)² = a² − 2ab + b² to find 83².
9. 9.Use a² − b² = (a + b)(a − b) to find 79² − 56².
10. 10.Use (a − b)² = a² − 2ab + b² to find 38².
11. 11.Use (a + b)(a − b) = a² − b² to find 39 × 21.
12. 12.Use (a − b)² = a² − 2ab + b² to find 78².
13. 13.If a + b = 14 and ab = 45, what is a² + b²?
14. 14.Use (a − b)² = a² − 2ab + b² to find 68².
15. 15.Find the value of x² − 2xy + y² when x = 5 and y = 4.
16. 16.Use (a − b)² = a² − 2ab + b² to find 37².
17. 17.Find the value of x² + 2xy + y² when x = 3 and y = 2.
18. 18.Use (a − b)² = a² − 2ab + b² to find 85².
19. 19.Use (a + b)² = a² + 2ab + b² to find 29².
20. 20.Use a² − b² = (a + b)(a − b) to find 33² − 23².
21. 21.Use a² − b² = (a + b)(a − b) to find 73² − 7².
22. 22.Use (a + b)² = a² + 2ab + b² to find 63².
23. 23.Use (a + b)(a − b) = a² − b² to find 27 × 13.
24. 24.Use (a − b)² = a² − 2ab + b² to find 46².
25. 25.Use (a − b)² = a² − 2ab + b² to find 22².
26. 26.Use (a + b)(a − b) = a² − b² to find 89 × 71.
27. 27.If a + b = 4 and ab = 3, what is a² + b²?
28. 28.Use a² − b² = (a + b)(a − b) to find 38² − 30².
29. 29.If a − b = 1 and ab = 42, what is a² + b²?
30. 30.Find the value of x² − 2xy + y² when x = 10 and y = 2.
31. 31.Use (a + b)² = a² + 2ab + b² to find 76².
32. 32.Use (a + b)² = a² + 2ab + b² to find 28².
33. 33.Use a² − b² = (a + b)(a − b) to find 57² − 39².
34. 34.Use (a − b)² = a² − 2ab + b² to find 19².
35. 35.Use (a + b)² = a² + 2ab + b² to find 78².
36. 36.Use a² − b² = (a + b)(a − b) to find 56² − 6².
37. 37.Use (a − b)² = a² − 2ab + b² to find 72².
38. 38.Find the value of x² − y² when x = 5 and y = 2.
39. 39.If a − b = 5 and ab = 6, what is a² + b²?
40. 40.Use (a + b)² = a² + 2ab + b² to find 103².

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