Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 247 · 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 99².
2. 2.Use (a − b)² = a² − 2ab + b² to find 57².
3. 3.Find the value of x² − y² when x = 4 and y = 3.
4. 4.If a + b = 5 and ab = 4, what is a² + b²?
5. 5.If a + b = 10 and ab = 16, what is a² + b²?
6. 6.Use (a + b)(a − b) = a² − b² to find 76 × 64.
7. 7.Use (a + b)² = a² + 2ab + b² to find 64².
8. 8.Use (a + b)² = a² + 2ab + b² to find 63².
9. 9.Use a² − b² = (a + b)(a − b) to find 96² − 6².
10. 10.Use a² − b² = (a + b)(a − b) to find 86² − 10².
11. 11.If a + b = 8 and ab = 12, what is a² + b²?
12. 12.Use a² − b² = (a + b)(a − b) to find 27² − 19².
13. 13.Use a² − b² = (a + b)(a − b) to find 81² − 13².
14. 14.Use (a + b)(a − b) = a² − b² to find 27 × 13.
15. 15.Use (a − b)² = a² − 2ab + b² to find 32².
16. 16.Find the value of x² − 2xy + y² when x = 6 and y = 1.
17. 17.Use (a + b)(a − b) = a² − b² to find 89 × 71.
18. 18.Find the value of x² + 2xy + y² when x = 3 and y = 2.
19. 19.If a + b = 3 and ab = 2, what is a² + b²?
20. 20.Find the value of x² + 2xy + y² when x = 14 and y = 6.
21. 21.Use (a − b)² = a² − 2ab + b² to find 82².
22. 22.If a + b = 5 and ab = 6, what is a² + b²?
23. 23.Use (a + b)(a − b) = a² − b² to find 101 × 99.
24. 24.Use (a + b)(a − b) = a² − b² to find 91 × 89.
25. 25.Use (a + b)(a − b) = a² − b² to find 36 × 24.
26. 26.Find the value of x² − 2xy + y² when x = 5 and y = 1.
27. 27.If a + b = 17 and ab = 72, what is a² + b²?
28. 28.Use (a + b)(a − b) = a² − b² to find 92 × 88.
29. 29.Use (a − b)² = a² − 2ab + b² to find 24².
30. 30.If a − b = 1 and ab = 2, what is a² + b²?
31. 31.Use (a + b)(a − b) = a² − b² to find 74 × 66.
32. 32.Use a² − b² = (a + b)(a − b) to find 42² − 3².
33. 33.Use a² − b² = (a + b)(a − b) to find 34² − 4².
34. 34.If a − b = 7 and ab = 44, what is a² + b²?
35. 35.Use (a + b)² = a² + 2ab + b² to find 82².
36. 36.Find the value of x² − 2xy + y² when x = 8 and y = 7.
37. 37.Use a² − b² = (a + b)(a − b) to find 97² − 27².
38. 38.Use a² − b² = (a + b)(a − b) to find 92² − 5².
39. 39.Find the value of x² − 2xy + y² when x = 4 and y = 1.
40. 40.If a + b = 11 and ab = 30, what is a² + b²?

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