Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 971 · 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)(a − b) = a² − b² to find 63 × 57.
2. 2.Use (a − b)² = a² − 2ab + b² to find 15².
3. 3.Use (a + b)² = a² + 2ab + b² to find 67².
4. 4.Use (a + b)² = a² + 2ab + b² to find 35².
5. 5.Use (a + b)(a − b) = a² − b² to find 56 × 44.
6. 6.Use (a − b)² = a² − 2ab + b² to find 33².
7. 7.Use a² − b² = (a + b)(a − b) to find 66² − 45².
8. 8.Find the value of x² + 2xy + y² when x = 5 and y = 1.
9. 9.Find the value of x² + 2xy + y² when x = 7 and y = 1.
10. 10.Use (a − b)² = a² − 2ab + b² to find 36².
11. 11.Use a² − b² = (a + b)(a − b) to find 51² − 16².
12. 12.Use (a − b)² = a² − 2ab + b² to find 63².
13. 13.Use (a + b)² = a² + 2ab + b² to find 86².
14. 14.If a − b = 5 and ab = 24, what is a² + b²?
15. 15.Use (a + b)² = a² + 2ab + b² to find 72².
16. 16.Use (a + b)² = a² + 2ab + b² to find 17².
17. 17.Use a² − b² = (a + b)(a − b) to find 20² − 15².
18. 18.Find the value of x² − y² when x = 15 and y = 3.
19. 19.Use (a − b)² = a² − 2ab + b² to find 21².
20. 20.Use (a + b)(a − b) = a² − b² to find 43 × 37.
21. 21.Use (a − b)² = a² − 2ab + b² to find 68².
22. 22.Find the value of x² − 2xy + y² when x = 10 and y = 7.
23. 23.If a − b = 1 and ab = 2, what is a² + b²?
24. 24.If a + b = 12 and ab = 27, what is a² + b²?
25. 25.Use a² − b² = (a + b)(a − b) to find 31² − 28².
26. 26.Find the value of x² + 2xy + y² when x = 3 and y = 1.
27. 27.Use (a − b)² = a² − 2ab + b² to find 29².
28. 28.Use a² − b² = (a + b)(a − b) to find 85² − 9².
29. 29.Use (a − b)² = a² − 2ab + b² to find 91².
30. 30.Use (a + b)(a − b) = a² − b² to find 73 × 67.
31. 31.Use (a − b)² = a² − 2ab + b² to find 66².
32. 32.Use (a + b)² = a² + 2ab + b² to find 79².
33. 33.Use (a + b)(a − b) = a² − b² to find 44 × 36.
34. 34.Use a² − b² = (a + b)(a − b) to find 24² − 11².
35. 35.If a − b = 1 and ab = 6, what is a² + b²?
36. 36.If a + b = 4 and ab = 3, what is a² + b²?
37. 37.Find the value of x² − y² when x = 8 and y = 7.
38. 38.Find the value of x² + 2xy + y² when x = 5 and y = 4.
39. 39.Use (a + b)² = a² + 2ab + b² to find 39².
40. 40.Use (a + b)² = a² + 2ab + b² to find 109².

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