Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 558 · 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 98² − 80².
2. 2.Use (a + b)² = a² + 2ab + b² to find 46².
3. 3.Use (a − b)² = a² − 2ab + b² to find 37².
4. 4.Use (a + b)(a − b) = a² − b² to find 92 × 88.
5. 5.Use a² − b² = (a + b)(a − b) to find 91² − 3².
6. 6.If a − b = 10 and ab = 11, what is a² + b²?
7. 7.If a − b = 5 and ab = 84, what is a² + b²?
8. 8.Use (a + b)(a − b) = a² − b² to find 48 × 32.
9. 9.Find the value of x² + 2xy + y² when x = 6 and y = 3.
10. 10.Use (a + b)² = a² + 2ab + b² to find 85².
11. 11.Use a² − b² = (a + b)(a − b) to find 90² − 61².
12. 12.If a + b = 12 and ab = 20, what is a² + b²?
13. 13.Use a² − b² = (a + b)(a − b) to find 24² − 19².
14. 14.Find the value of x² + 2xy + y² when x = 3 and y = 1.
15. 15.Use (a − b)² = a² − 2ab + b² to find 58².
16. 16.If a − b = 2 and ab = 3, what is a² + b²?
17. 17.Find the value of x² + 2xy + y² when x = 4 and y = 3.
18. 18.Use (a − b)² = a² − 2ab + b² to find 23².
19. 19.Use (a + b)² = a² + 2ab + b² to find 51².
20. 20.If a + b = 6 and ab = 8, what is a² + b²?
21. 21.Use (a + b)(a − b) = a² − b² to find 104 × 96.
22. 22.If a + b = 6 and ab = 5, what is a² + b²?
23. 23.Use (a + b)² = a² + 2ab + b² to find 17².
24. 24.Use (a − b)² = a² − 2ab + b² to find 69².
25. 25.Use (a + b)² = a² + 2ab + b² to find 22².
26. 26.Use a² − b² = (a + b)(a − b) to find 90² − 34².
27. 27.Find the value of x² + 2xy + y² when x = 7 and y = 3.
28. 28.Find the value of x² − y² when x = 15 and y = 5.
29. 29.Use (a + b)² = a² + 2ab + b² to find 12².
30. 30.Use (a + b)² = a² + 2ab + b² to find 105².
31. 31.If a − b = 2 and ab = 15, what is a² + b²?
32. 32.Find the value of x² − y² when x = 11 and y = 5.
33. 33.Use (a + b)(a − b) = a² − b² to find 41 × 39.
34. 34.Find the value of x² − y² when x = 12 and y = 2.
35. 35.Use a² − b² = (a + b)(a − b) to find 67² − 66².
36. 36.If a + b = 17 and ab = 72, what is a² + b²?
37. 37.If a − b = 7 and ab = 8, what is a² + b²?
38. 38.Use (a + b)(a − b) = a² − b² to find 21 × 19.
39. 39.Use (a − b)² = a² − 2ab + b² to find 19².
40. 40.Use a² − b² = (a + b)(a − b) to find 59² − 13².

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