Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 578 · 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 a² − b² = (a + b)(a − b) to find 73² − 27².
2. 2.If a − b = 1 and ab = 12, what is a² + b²?
3. 3.Find the value of x² + 2xy + y² when x = 11 and y = 5.
4. 4.Use (a + b)(a − b) = a² − b² to find 96 × 84.
5. 5.If a + b = 8 and ab = 7, what is a² + b²?
6. 6.Find the value of x² + 2xy + y² when x = 12 and y = 5.
7. 7.Use (a − b)² = a² − 2ab + b² to find 11².
8. 8.Use (a + b)² = a² + 2ab + b² to find 81².
9. 9.Use (a − b)² = a² − 2ab + b² to find 15².
10. 10.Use (a + b)(a − b) = a² − b² to find 32 × 28.
11. 11.Use (a − b)² = a² − 2ab + b² to find 39².
12. 12.Find the value of x² − 2xy + y² when x = 7 and y = 1.
13. 13.Use (a + b)² = a² + 2ab + b² to find 47².
14. 14.Use (a − b)² = a² − 2ab + b² to find 91².
15. 15.If a + b = 16 and ab = 48, what is a² + b²?
16. 16.Use (a + b)² = a² + 2ab + b² to find 18².
17. 17.Use (a + b)² = a² + 2ab + b² to find 64².
18. 18.If a − b = 2 and ab = 3, what is a² + b²?
19. 19.Find the value of x² − 2xy + y² when x = 3 and y = 1.
20. 20.Use (a + b)² = a² + 2ab + b² to find 103².
21. 21.Use (a + b)(a − b) = a² − b² to find 61 × 59.
22. 22.Use (a − b)² = a² − 2ab + b² to find 95².
23. 23.Use a² − b² = (a + b)(a − b) to find 20² − 10².
24. 24.Use (a + b)² = a² + 2ab + b² to find 27².
25. 25.If a − b = 1 and ab = 72, what is a² + b²?
26. 26.Use (a + b)² = a² + 2ab + b² to find 108².
27. 27.Use (a − b)² = a² − 2ab + b² to find 27².
28. 28.Use a² − b² = (a + b)(a − b) to find 63² − 47².
29. 29.If a − b = 2 and ab = 24, what is a² + b²?
30. 30.Use (a + b)² = a² + 2ab + b² to find 101².
31. 31.Use (a + b)(a − b) = a² − b² to find 49 × 31.
32. 32.Find the value of x² + 2xy + y² when x = 8 and y = 2.
33. 33.Use a² − b² = (a + b)(a − b) to find 36² − 1².
34. 34.Use (a + b)(a − b) = a² − b² to find 41 × 39.
35. 35.Find the value of x² + 2xy + y² when x = 3 and y = 2.
36. 36.Use (a + b)² = a² + 2ab + b² to find 26².
37. 37.Use (a + b)(a − b) = a² − b² to find 84 × 76.
38. 38.Use a² − b² = (a + b)(a − b) to find 27² − 11².
39. 39.Use (a − b)² = a² − 2ab + b² to find 14².
40. 40.Use (a + b)(a − b) = a² − b² to find 37 × 23.

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