Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 10 · 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 = 1 and ab = 2, what is a² + b²?
2. 2.Use a² − b² = (a + b)(a − b) to find 85² − 35².
3. 3.If a + b = 5 and ab = 4, what is a² + b²?
4. 4.Use (a − b)² = a² − 2ab + b² to find 68².
5. 5.If a + b = 3 and ab = 2, what is a² + b²?
6. 6.Use (a + b)² = a² + 2ab + b² to find 73².
7. 7.Use (a + b)² = a² + 2ab + b² to find 58².
8. 8.Use (a + b)² = a² + 2ab + b² to find 67².
9. 9.Use (a + b)² = a² + 2ab + b² to find 44².
10. 10.If a + b = 10 and ab = 9, what is a² + b²?
11. 11.Use (a + b)² = a² + 2ab + b² to find 27².
12. 12.Use (a + b)² = a² + 2ab + b² to find 106².
13. 13.If a + b = 7 and ab = 12, what is a² + b²?
14. 14.Use (a + b)(a − b) = a² − b² to find 94 × 86.
15. 15.Use (a − b)² = a² − 2ab + b² to find 42².
16. 16.Use (a + b)² = a² + 2ab + b² to find 83².
17. 17.Use (a + b)² = a² + 2ab + b² to find 21².
18. 18.Use a² − b² = (a + b)(a − b) to find 90² − 30².
19. 19.Use (a + b)(a − b) = a² − b² to find 75 × 65.
20. 20.Use (a + b)² = a² + 2ab + b² to find 64².
21. 21.Use a² − b² = (a + b)(a − b) to find 45² − 4².
22. 22.Find the value of x² + 2xy + y² when x = 10 and y = 7.
23. 23.Use (a + b)² = a² + 2ab + b² to find 104².
24. 24.If a − b = 5 and ab = 14, what is a² + b²?
25. 25.Use a² − b² = (a + b)(a − b) to find 82² − 41².
26. 26.Use (a + b)² = a² + 2ab + b² to find 35².
27. 27.Use a² − b² = (a + b)(a − b) to find 54² − 24².
28. 28.Use a² − b² = (a + b)(a − b) to find 46² − 41².
29. 29.Use (a + b)(a − b) = a² − b² to find 27 × 13.
30. 30.Use (a + b)(a − b) = a² − b² to find 83 × 77.
31. 31.Use (a − b)² = a² − 2ab + b² to find 95².
32. 32.Use (a − b)² = a² − 2ab + b² to find 41².
33. 33.Use (a + b)(a − b) = a² − b² to find 46 × 34.
34. 34.Use (a + b)² = a² + 2ab + b² to find 46².
35. 35.Use (a − b)² = a² − 2ab + b² to find 65².
36. 36.Use a² − b² = (a + b)(a − b) to find 20² − 19².
37. 37.Use (a + b)(a − b) = a² − b² to find 28 × 12.
38. 38.If a + b = 19 and ab = 88, what is a² + b²?
39. 39.Use (a − b)² = a² − 2ab + b² to find 18².
40. 40.Use a² − b² = (a + b)(a − b) to find 47² − 10².

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