Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 221 · 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 32² − 7².
2. 2.Find the value of x² + 2xy + y² when x = 5 and y = 3.
3. 3.Use (a − b)² = a² − 2ab + b² to find 77².
4. 4.Find the value of x² + 2xy + y² when x = 4 and y = 1.
5. 5.Use (a − b)² = a² − 2ab + b² to find 11².
6. 6.Find the value of x² + 2xy + y² when x = 13 and y = 11.
7. 7.Use a² − b² = (a + b)(a − b) to find 27² − 18².
8. 8.Use (a + b)(a − b) = a² − b² to find 73 × 67.
9. 9.Use (a + b)² = a² + 2ab + b² to find 51².
10. 10.Use (a − b)² = a² − 2ab + b² to find 14².
11. 11.Use (a + b)(a − b) = a² − b² to find 31 × 29.
12. 12.Use (a − b)² = a² − 2ab + b² to find 48².
13. 13.Use (a + b)² = a² + 2ab + b² to find 74².
14. 14.Use (a − b)² = a² − 2ab + b² to find 29².
15. 15.Use (a + b)(a − b) = a² − b² to find 23 × 17.
16. 16.Use (a + b)² = a² + 2ab + b² to find 73².
17. 17.Use (a − b)² = a² − 2ab + b² to find 99².
18. 18.Use (a + b)² = a² + 2ab + b² to find 66².
19. 19.Use (a + b)(a − b) = a² − b² to find 94 × 86.
20. 20.Use a² − b² = (a + b)(a − b) to find 84² − 1².
21. 21.Use a² − b² = (a + b)(a − b) to find 65² − 20².
22. 22.Use (a + b)² = a² + 2ab + b² to find 32².
23. 23.If a − b = 3 and ab = 54, what is a² + b²?
24. 24.Find the value of x² − 2xy + y² when x = 5 and y = 4.
25. 25.Use (a + b)(a − b) = a² − b² to find 77 × 63.
26. 26.Use (a − b)² = a² − 2ab + b² to find 25².
27. 27.Use (a + b)² = a² + 2ab + b² to find 75².
28. 28.Find the value of x² − y² when x = 9 and y = 4.
29. 29.Find the value of x² + 2xy + y² when x = 14 and y = 10.
30. 30.Use a² − b² = (a + b)(a − b) to find 79² − 36².
31. 31.Find the value of x² + 2xy + y² when x = 11 and y = 3.
32. 32.Use (a + b)(a − b) = a² − b² to find 84 × 76.
33. 33.Find the value of x² − y² when x = 9 and y = 8.
34. 34.Use (a + b)(a − b) = a² − b² to find 28 × 12.
35. 35.Use (a + b)² = a² + 2ab + b² to find 87².
36. 36.Use (a + b)(a − b) = a² − b² to find 87 × 73.
37. 37.Find the value of x² − 2xy + y² when x = 6 and y = 5.
38. 38.If a − b = 7 and ab = 18, what is a² + b²?
39. 39.Use a² − b² = (a + b)(a − b) to find 99² − 59².
40. 40.Use (a + b)² = a² + 2ab + b² to find 48².

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