Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 465 · 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 55 × 45.
2. 2.If a + b = 3 and ab = 2, what is a² + b²?
3. 3.Use (a − b)² = a² − 2ab + b² to find 97².
4. 4.Use (a + b)² = a² + 2ab + b² to find 19².
5. 5.Find the value of x² − y² when x = 5 and y = 1.
6. 6.Use a² − b² = (a + b)(a − b) to find 78² − 49².
7. 7.Use (a − b)² = a² − 2ab + b² to find 41².
8. 8.If a − b = 4 and ab = 5, what is a² + b²?
9. 9.If a + b = 10 and ab = 9, what is a² + b²?
10. 10.Use (a + b)(a − b) = a² − b² to find 43 × 37.
11. 11.If a − b = 5 and ab = 24, what is a² + b²?
12. 12.Use a² − b² = (a + b)(a − b) to find 86² − 10².
13. 13.If a − b = 1 and ab = 2, what is a² + b²?
14. 14.Use (a − b)² = a² − 2ab + b² to find 33².
15. 15.If a + b = 11 and ab = 18, what is a² + b²?
16. 16.Find the value of x² + 2xy + y² when x = 3 and y = 1.
17. 17.Use a² − b² = (a + b)(a − b) to find 53² − 4².
18. 18.Use (a + b)² = a² + 2ab + b² to find 59².
19. 19.Use (a + b)(a − b) = a² − b² to find 91 × 89.
20. 20.Use (a + b)² = a² + 2ab + b² to find 62².
21. 21.Use (a + b)(a − b) = a² − b² to find 77 × 63.
22. 22.Find the value of x² − y² when x = 6 and y = 2.
23. 23.Use a² − b² = (a + b)(a − b) to find 26² − 4².
24. 24.If a + b = 18 and ab = 80, what is a² + b²?
25. 25.Find the value of x² − 2xy + y² when x = 10 and y = 9.
26. 26.Use (a − b)² = a² − 2ab + b² to find 16².
27. 27.Use a² − b² = (a + b)(a − b) to find 54² − 23².
28. 28.Use (a + b)² = a² + 2ab + b² to find 94².
29. 29.Use (a − b)² = a² − 2ab + b² to find 88².
30. 30.Use a² − b² = (a + b)(a − b) to find 53² − 29².
31. 31.Use (a + b)(a − b) = a² − b² to find 25 × 15.
32. 32.If a + b = 10 and ab = 16, what is a² + b²?
33. 33.Find the value of x² − y² when x = 12 and y = 1.
34. 34.Use a² − b² = (a + b)(a − b) to find 94² − 87².
35. 35.Find the value of x² − 2xy + y² when x = 11 and y = 7.
36. 36.If a + b = 18 and ab = 72, what is a² + b²?
37. 37.Use (a + b)² = a² + 2ab + b² to find 58².
38. 38.Use (a + b)² = a² + 2ab + b² to find 28².
39. 39.Use (a − b)² = a² − 2ab + b² to find 75².
40. 40.Use (a + b)² = a² + 2ab + b² to find 99².

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