Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 580 · 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 28².
2. 2.Use (a + b)² = a² + 2ab + b² to find 68².
3. 3.Use (a + b)² = a² + 2ab + b² to find 39².
4. 4.If a − b = 9 and ab = 10, what is a² + b²?
5. 5.Find the value of x² − y² when x = 7 and y = 1.
6. 6.Use a² − b² = (a + b)(a − b) to find 28² − 22².
7. 7.If a + b = 11 and ab = 30, what is a² + b²?
8. 8.Use (a + b)² = a² + 2ab + b² to find 56².
9. 9.Use (a + b)(a − b) = a² − b² to find 61 × 59.
10. 10.If a − b = 7 and ab = 30, what is a² + b²?
11. 11.Use (a + b)² = a² + 2ab + b² to find 85².
12. 12.Use (a − b)² = a² − 2ab + b² to find 29².
13. 13.Find the value of x² + 2xy + y² when x = 4 and y = 3.
14. 14.Find the value of x² + 2xy + y² when x = 7 and y = 1.
15. 15.If a + b = 18 and ab = 72, what is a² + b²?
16. 16.Use (a + b)² = a² + 2ab + b² to find 84².
17. 17.If a + b = 10 and ab = 24, what is a² + b²?
18. 18.If a − b = 5 and ab = 6, what is a² + b²?
19. 19.Use (a + b)² = a² + 2ab + b² to find 33².
20. 20.Find the value of x² − 2xy + y² when x = 6 and y = 3.
21. 21.Use (a + b)(a − b) = a² − b² to find 52 × 48.
22. 22.If a + b = 5 and ab = 6, what is a² + b²?
23. 23.If a − b = 5 and ab = 14, what is a² + b²?
24. 24.Use (a + b)(a − b) = a² − b² to find 73 × 67.
25. 25.Use (a − b)² = a² − 2ab + b² to find 98².
26. 26.Use (a + b)² = a² + 2ab + b² to find 29².
27. 27.Use a² − b² = (a + b)(a − b) to find 63² − 12².
28. 28.If a − b = 6 and ab = 16, what is a² + b²?
29. 29.Use a² − b² = (a + b)(a − b) to find 27² − 8².
30. 30.Use (a + b)(a − b) = a² − b² to find 39 × 21.
31. 31.Use (a + b)² = a² + 2ab + b² to find 73².
32. 32.Use (a − b)² = a² − 2ab + b² to find 31².
33. 33.Use (a + b)² = a² + 2ab + b² to find 82².
34. 34.Use (a + b)(a − b) = a² − b² to find 23 × 17.
35. 35.Use (a + b)² = a² + 2ab + b² to find 41².
36. 36.Use (a + b)² = a² + 2ab + b² to find 32².
37. 37.Find the value of x² − y² when x = 11 and y = 7.
38. 38.Use (a − b)² = a² − 2ab + b² to find 27².
39. 39.Use a² − b² = (a + b)(a − b) to find 44² − 35².
40. 40.Use a² − b² = (a + b)(a − b) to find 33² − 12².

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