Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 389 · 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 97².
2. 2.Use (a + b)(a − b) = a² − b² to find 81 × 79.
3. 3.Use (a + b)² = a² + 2ab + b² to find 88².
4. 4.Use (a − b)² = a² − 2ab + b² to find 96².
5. 5.If a + b = 14 and ab = 24, what is a² + b²?
6. 6.Use (a + b)² = a² + 2ab + b² to find 89².
7. 7.Use a² − b² = (a + b)(a − b) to find 82² − 2².
8. 8.Use (a + b)² = a² + 2ab + b² to find 25².
9. 9.Use (a − b)² = a² − 2ab + b² to find 65².
10. 10.Find the value of x² + 2xy + y² when x = 12 and y = 7.
11. 11.Find the value of x² + 2xy + y² when x = 12 and y = 9.
12. 12.Find the value of x² + 2xy + y² when x = 14 and y = 12.
13. 13.Use a² − b² = (a + b)(a − b) to find 73² − 60².
14. 14.Use a² − b² = (a + b)(a − b) to find 70² − 52².
15. 15.Use (a − b)² = a² − 2ab + b² to find 58².
16. 16.Use (a + b)(a − b) = a² − b² to find 44 × 36.
17. 17.Use a² − b² = (a + b)(a − b) to find 79² − 5².
18. 18.Use (a − b)² = a² − 2ab + b² to find 27².
19. 19.Find the value of x² − 2xy + y² when x = 12 and y = 4.
20. 20.Find the value of x² + 2xy + y² when x = 6 and y = 4.
21. 21.Use (a − b)² = a² − 2ab + b² to find 29².
22. 22.Use (a + b)(a − b) = a² − b² to find 39 × 21.
23. 23.Use (a + b)² = a² + 2ab + b² to find 82².
24. 24.Use (a − b)² = a² − 2ab + b² to find 63².
25. 25.Use a² − b² = (a + b)(a − b) to find 59² − 21².
26. 26.Use (a + b)² = a² + 2ab + b² to find 39².
27. 27.Use (a + b)² = a² + 2ab + b² to find 41².
28. 28.Find the value of x² + 2xy + y² when x = 3 and y = 2.
29. 29.Use (a − b)² = a² − 2ab + b² to find 64².
30. 30.Use (a − b)² = a² − 2ab + b² to find 26².
31. 31.Find the value of x² + 2xy + y² when x = 7 and y = 6.
32. 32.If a + b = 6 and ab = 8, what is a² + b²?
33. 33.Use (a + b)² = a² + 2ab + b² to find 36².
34. 34.Use a² − b² = (a + b)(a − b) to find 99² − 74².
35. 35.Use (a − b)² = a² − 2ab + b² to find 85².
36. 36.If a + b = 11 and ab = 24, what is a² + b²?
37. 37.If a + b = 3 and ab = 2, what is a² + b²?
38. 38.Use (a − b)² = a² − 2ab + b² to find 47².
39. 39.Find the value of x² + 2xy + y² when x = 5 and y = 2.
40. 40.If a + b = 15 and ab = 50, what is a² + b²?

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