Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 384 · 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 21².
2. 2.Use a² − b² = (a + b)(a − b) to find 57² − 41².
3. 3.If a + b = 5 and ab = 4, what is a² + b²?
4. 4.If a − b = 4 and ab = 12, what is a² + b²?
5. 5.Use a² − b² = (a + b)(a − b) to find 24² − 7².
6. 6.Use a² − b² = (a + b)(a − b) to find 99² − 42².
7. 7.Use a² − b² = (a + b)(a − b) to find 35² − 10².
8. 8.Use a² − b² = (a + b)(a − b) to find 86² − 14².
9. 9.Find the value of x² − 2xy + y² when x = 6 and y = 1.
10. 10.Use (a + b)(a − b) = a² − b² to find 46 × 34.
11. 11.Use (a + b)² = a² + 2ab + b² to find 59².
12. 12.Use a² − b² = (a + b)(a − b) to find 52² − 27².
13. 13.Use a² − b² = (a + b)(a − b) to find 43² − 40².
14. 14.If a + b = 9 and ab = 20, what is a² + b²?
15. 15.Use (a + b)(a − b) = a² − b² to find 25 × 15.
16. 16.Use (a + b)(a − b) = a² − b² to find 95 × 85.
17. 17.Find the value of x² − 2xy + y² when x = 5 and y = 4.
18. 18.Find the value of x² − y² when x = 11 and y = 4.
19. 19.Find the value of x² − 2xy + y² when x = 11 and y = 9.
20. 20.Use (a − b)² = a² − 2ab + b² to find 94².
21. 21.Use (a − b)² = a² − 2ab + b² to find 43².
22. 22.Use (a − b)² = a² − 2ab + b² to find 27².
23. 23.Find the value of x² − 2xy + y² when x = 14 and y = 8.
24. 24.Use (a + b)² = a² + 2ab + b² to find 103².
25. 25.Use (a + b)² = a² + 2ab + b² to find 53².
26. 26.Use (a + b)² = a² + 2ab + b² to find 93².
27. 27.Use (a − b)² = a² − 2ab + b² to find 58².
28. 28.Use (a − b)² = a² − 2ab + b² to find 52².
29. 29.Find the value of x² − 2xy + y² when x = 4 and y = 2.
30. 30.Use (a + b)² = a² + 2ab + b² to find 51².
31. 31.Find the value of x² − y² when x = 8 and y = 3.
32. 32.Find the value of x² + 2xy + y² when x = 11 and y = 2.
33. 33.Use (a − b)² = a² − 2ab + b² to find 25².
34. 34.Use (a + b)(a − b) = a² − b² to find 65 × 55.
35. 35.Use a² − b² = (a + b)(a − b) to find 31² − 4².
36. 36.Use (a + b)(a − b) = a² − b² to find 51 × 49.
37. 37.Find the value of x² − y² when x = 6 and y = 4.
38. 38.Use (a + b)(a − b) = a² − b² to find 107 × 93.
39. 39.Find the value of x² + 2xy + y² when x = 5 and y = 2.
40. 40.Use (a + b)(a − b) = a² − b² to find 87 × 73.

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