Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 642 · 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 26 × 14.
2. 2.Use (a + b)(a − b) = a² − b² to find 91 × 89.
3. 3.Use (a + b)² = a² + 2ab + b² to find 47².
4. 4.Use (a + b)² = a² + 2ab + b² to find 71².
5. 5.Use a² − b² = (a + b)(a − b) to find 23² − 1².
6. 6.Use (a + b)² = a² + 2ab + b² to find 56².
7. 7.Use (a + b)² = a² + 2ab + b² to find 21².
8. 8.Use (a − b)² = a² − 2ab + b² to find 51².
9. 9.Use (a − b)² = a² − 2ab + b² to find 41².
10. 10.Use (a − b)² = a² − 2ab + b² to find 86².
11. 11.Find the value of x² + 2xy + y² when x = 8 and y = 1.
12. 12.If a − b = 2 and ab = 3, what is a² + b²?
13. 13.Use (a + b)(a − b) = a² − b² to find 27 × 13.
14. 14.Use a² − b² = (a + b)(a − b) to find 47² − 3².
15. 15.If a + b = 3 and ab = 2, what is a² + b²?
16. 16.Use (a − b)² = a² − 2ab + b² to find 22².
17. 17.If a + b = 17 and ab = 60, what is a² + b²?
18. 18.If a + b = 16 and ab = 63, what is a² + b²?
19. 19.Find the value of x² + 2xy + y² when x = 4 and y = 1.
20. 20.Find the value of x² + 2xy + y² when x = 14 and y = 13.
21. 21.Use (a + b)(a − b) = a² − b² to find 32 × 28.
22. 22.Use (a + b)² = a² + 2ab + b² to find 27².
23. 23.Use (a + b)(a − b) = a² − b² to find 107 × 93.
24. 24.If a + b = 14 and ab = 24, what is a² + b²?
25. 25.Use (a + b)² = a² + 2ab + b² to find 41².
26. 26.Use (a + b)² = a² + 2ab + b² to find 104².
27. 27.Use (a + b)(a − b) = a² − b² to find 74 × 66.
28. 28.If a + b = 7 and ab = 12, what is a² + b²?
29. 29.Use (a + b)² = a² + 2ab + b² to find 75².
30. 30.Use (a − b)² = a² − 2ab + b² to find 29².
31. 31.Use a² − b² = (a + b)(a − b) to find 36² − 4².
32. 32.Find the value of x² − y² when x = 12 and y = 1.
33. 33.Use (a + b)(a − b) = a² − b² to find 23 × 17.
34. 34.If a + b = 16 and ab = 55, what is a² + b²?
35. 35.Use (a + b)² = a² + 2ab + b² to find 97².
36. 36.Find the value of x² − y² when x = 7 and y = 1.
37. 37.Find the value of x² − 2xy + y² when x = 5 and y = 3.
38. 38.Use (a + b)² = a² + 2ab + b² to find 65².
39. 39.Use (a − b)² = a² − 2ab + b² to find 49².
40. 40.If a + b = 12 and ab = 20, what is a² + b²?

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