Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 820 · 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 21² − 12².
2. 2.Use a² − b² = (a + b)(a − b) to find 98² − 19².
3. 3.Use (a − b)² = a² − 2ab + b² to find 42².
4. 4.Use a² − b² = (a + b)(a − b) to find 95² − 70².
5. 5.Use (a + b)² = a² + 2ab + b² to find 79².
6. 6.Use (a − b)² = a² − 2ab + b² to find 39².
7. 7.If a − b = 2 and ab = 63, what is a² + b²?
8. 8.Use (a − b)² = a² − 2ab + b² to find 41².
9. 9.Use (a + b)(a − b) = a² − b² to find 29 × 11.
10. 10.Use (a − b)² = a² − 2ab + b² to find 82².
11. 11.If a − b = 8 and ab = 33, what is a² + b²?
12. 12.Use (a + b)(a − b) = a² − b² to find 58 × 42.
13. 13.If a + b = 15 and ab = 56, what is a² + b²?
14. 14.Use (a + b)(a − b) = a² − b² to find 102 × 98.
15. 15.Find the value of x² + 2xy + y² when x = 14 and y = 7.
16. 16.Use (a + b)² = a² + 2ab + b² to find 32².
17. 17.Use (a − b)² = a² − 2ab + b² to find 11².
18. 18.Find the value of x² − 2xy + y² when x = 3 and y = 2.
19. 19.If a − b = 5 and ab = 14, what is a² + b²?
20. 20.Use (a + b)² = a² + 2ab + b² to find 63².
21. 21.Use (a + b)² = a² + 2ab + b² to find 13².
22. 22.Use (a − b)² = a² − 2ab + b² to find 65².
23. 23.Use (a + b)(a − b) = a² − b² to find 43 × 37.
24. 24.If a + b = 6 and ab = 5, what is a² + b²?
25. 25.Use (a + b)² = a² + 2ab + b² to find 65².
26. 26.Use (a + b)² = a² + 2ab + b² to find 49².
27. 27.If a + b = 12 and ab = 20, what is a² + b²?
28. 28.Use (a + b)(a − b) = a² − b² to find 65 × 55.
29. 29.Use (a + b)(a − b) = a² − b² to find 32 × 28.
30. 30.Find the value of x² + 2xy + y² when x = 3 and y = 2.
31. 31.Use (a − b)² = a² − 2ab + b² to find 98².
32. 32.Use (a + b)² = a² + 2ab + b² to find 55².
33. 33.Find the value of x² − 2xy + y² when x = 10 and y = 5.
34. 34.Use (a + b)² = a² + 2ab + b² to find 43².
35. 35.Use (a − b)² = a² − 2ab + b² to find 32².
36. 36.Use (a − b)² = a² − 2ab + b² to find 12².
37. 37.Use (a + b)² = a² + 2ab + b² to find 47².
38. 38.Use (a + b)(a − b) = a² − b² to find 38 × 22.
39. 39.Use (a − b)² = a² − 2ab + b² to find 47².
40. 40.Use (a + b)(a − b) = a² − b² to find 61 × 59.

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