Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 29 · 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 (a + b)² = a² + 2ab + b² to find 31².
2. 2.If a − b = 8 and ab = 20, what is a² + b²?
3. 3.Use (a − b)² = a² − 2ab + b² to find 17².
4. 4.If a − b = 4 and ab = 12, what is a² + b²?
5. 5.Find the value of x² + 2xy + y² when x = 10 and y = 9.
6. 6.Use (a − b)² = a² − 2ab + b² to find 36².
7. 7.Use (a + b)² = a² + 2ab + b² to find 42².
8. 8.Use (a + b)² = a² + 2ab + b² to find 77².
9. 9.Find the value of x² + 2xy + y² when x = 11 and y = 6.
10. 10.If a − b = 2 and ab = 15, what is a² + b²?
11. 11.Find the value of x² − y² when x = 5 and y = 4.
12. 12.Use a² − b² = (a + b)(a − b) to find 97² − 63².
13. 13.Use a² − b² = (a + b)(a − b) to find 35² − 10².
14. 14.Use (a − b)² = a² − 2ab + b² to find 92².
15. 15.Find the value of x² − 2xy + y² when x = 11 and y = 5.
16. 16.Use (a + b)(a − b) = a² − b² to find 51 × 49.
17. 17.Find the value of x² + 2xy + y² when x = 4 and y = 1.
18. 18.Find the value of x² − 2xy + y² when x = 12 and y = 5.
19. 19.Use (a + b)² = a² + 2ab + b² to find 23².
20. 20.Find the value of x² − 2xy + y² when x = 6 and y = 4.
21. 21.Find the value of x² − 2xy + y² when x = 9 and y = 3.
22. 22.Use a² − b² = (a + b)(a − b) to find 34² − 31².
23. 23.If a + b = 5 and ab = 4, what is a² + b²?
24. 24.Use (a − b)² = a² − 2ab + b² to find 37².
25. 25.Use (a + b)(a − b) = a² − b² to find 98 × 82.
26. 26.Use (a − b)² = a² − 2ab + b² to find 64².
27. 27.Use (a + b)(a − b) = a² − b² to find 41 × 39.
28. 28.Use (a − b)² = a² − 2ab + b² to find 12².
29. 29.Use (a + b)(a − b) = a² − b² to find 39 × 21.
30. 30.Find the value of x² − y² when x = 9 and y = 3.
31. 31.Use (a − b)² = a² − 2ab + b² to find 11².
32. 32.Use (a + b)(a − b) = a² − b² to find 56 × 44.
33. 33.Find the value of x² + 2xy + y² when x = 5 and y = 1.
34. 34.Use (a + b)(a − b) = a² − b² to find 21 × 19.
35. 35.Use (a + b)² = a² + 2ab + b² to find 28².
36. 36.If a − b = 3 and ab = 4, what is a² + b²?
37. 37.Use (a + b)(a − b) = a² − b² to find 105 × 95.
38. 38.Find the value of x² − y² when x = 8 and y = 3.
39. 39.If a + b = 12 and ab = 11, what is a² + b²?
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