Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 15 · 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 = 7 and ab = 10, what is a² + b²?
2. 2.Use (a − b)² = a² − 2ab + b² to find 36².
3. 3.Find the value of x² − 2xy + y² when x = 10 and y = 1.
4. 4.Use a² − b² = (a + b)(a − b) to find 34² − 3².
5. 5.Use (a + b)² = a² + 2ab + b² to find 19².
6. 6.Use (a + b)² = a² + 2ab + b² to find 68².
7. 7.If a + b = 10 and ab = 24, what is a² + b²?
8. 8.Use a² − b² = (a + b)(a − b) to find 56² − 37².
9. 9.Use (a + b)(a − b) = a² − b² to find 21 × 19.
10. 10.If a − b = 1 and ab = 110, what is a² + b²?
11. 11.Use (a + b)² = a² + 2ab + b² to find 81².
12. 12.Use (a − b)² = a² − 2ab + b² to find 57².
13. 13.Use (a + b)(a − b) = a² − b² to find 92 × 88.
14. 14.If a + b = 8 and ab = 7, what is a² + b²?
15. 15.Use (a − b)² = a² − 2ab + b² to find 16².
16. 16.Find the value of x² − 2xy + y² when x = 13 and y = 11.
17. 17.Find the value of x² − 2xy + y² when x = 5 and y = 1.
18. 18.Use (a + b)(a − b) = a² − b² to find 41 × 39.
19. 19.Use a² − b² = (a + b)(a − b) to find 50² − 42².
20. 20.Use (a − b)² = a² − 2ab + b² to find 12².
21. 21.Find the value of x² − y² when x = 14 and y = 3.
22. 22.Find the value of x² − 2xy + y² when x = 8 and y = 7.
23. 23.Use a² − b² = (a + b)(a − b) to find 84² − 76².
24. 24.Use a² − b² = (a + b)(a − b) to find 45² − 31².
25. 25.If a + b = 13 and ab = 36, what is a² + b²?
26. 26.Find the value of x² + 2xy + y² when x = 13 and y = 6.
27. 27.Find the value of x² − y² when x = 7 and y = 4.
28. 28.Use (a + b)(a − b) = a² − b² to find 84 × 76.
29. 29.If a − b = 1 and ab = 42, what is a² + b²?
30. 30.Find the value of x² + 2xy + y² when x = 14 and y = 12.
31. 31.Use (a − b)² = a² − 2ab + b² to find 98².
32. 32.Use (a + b)² = a² + 2ab + b² to find 14².
33. 33.Find the value of x² − y² when x = 10 and y = 6.
34. 34.Use (a + b)² = a² + 2ab + b² to find 26².
35. 35.Find the value of x² − y² when x = 14 and y = 9.
36. 36.Use (a + b)(a − b) = a² − b² to find 29 × 11.
37. 37.Use (a − b)² = a² − 2ab + b² to find 55².
38. 38.Use (a + b)² = a² + 2ab + b² to find 71².
39. 39.Use a² − b² = (a + b)(a − b) to find 38² − 7².
40. 40.Use (a − b)² = a² − 2ab + b² to find 89².

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