Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 113 · 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 22² − 10².
2. 2.If a + b = 18 and ab = 72, what is a² + b²?
3. 3.Use (a + b)² = a² + 2ab + b² to find 28².
4. 4.Use (a + b)² = a² + 2ab + b² to find 103².
5. 5.Use a² − b² = (a + b)(a − b) to find 81² − 78².
6. 6.Find the value of x² − y² when x = 4 and y = 1.
7. 7.If a − b = 2 and ab = 35, what is a² + b²?
8. 8.Find the value of x² − 2xy + y² when x = 4 and y = 3.
9. 9.Use (a + b)² = a² + 2ab + b² to find 51².
10. 10.Use (a + b)(a − b) = a² − b² to find 28 × 12.
11. 11.Find the value of x² − y² when x = 11 and y = 8.
12. 12.Use a² − b² = (a + b)(a − b) to find 80² − 44².
13. 13.Use (a − b)² = a² − 2ab + b² to find 79².
14. 14.Use (a + b)² = a² + 2ab + b² to find 81².
15. 15.Use a² − b² = (a + b)(a − b) to find 85² − 40².
16. 16.Use (a + b)² = a² + 2ab + b² to find 12².
17. 17.If a + b = 10 and ab = 16, what is a² + b²?
18. 18.Use (a + b)² = a² + 2ab + b² to find 71².
19. 19.Use (a − b)² = a² − 2ab + b² to find 41².
20. 20.Use (a + b)(a − b) = a² − b² to find 109 × 91.
21. 21.Use (a + b)² = a² + 2ab + b² to find 43².
22. 22.Use (a + b)² = a² + 2ab + b² to find 108².
23. 23.Find the value of x² + 2xy + y² when x = 11 and y = 2.
24. 24.Use (a + b)² = a² + 2ab + b² to find 57².
25. 25.Find the value of x² − y² when x = 8 and y = 1.
26. 26.Use (a + b)² = a² + 2ab + b² to find 15².
27. 27.Use (a − b)² = a² − 2ab + b² to find 37².
28. 28.Use (a + b)² = a² + 2ab + b² to find 26².
29. 29.Use (a − b)² = a² − 2ab + b² to find 31².
30. 30.Use (a − b)² = a² − 2ab + b² to find 67².
31. 31.Find the value of x² − 2xy + y² when x = 10 and y = 2.
32. 32.Find the value of x² + 2xy + y² when x = 14 and y = 7.
33. 33.Use (a + b)(a − b) = a² − b² to find 22 × 18.
34. 34.Use (a − b)² = a² − 2ab + b² to find 77².
35. 35.Use (a − b)² = a² − 2ab + b² to find 18².
36. 36.Use a² − b² = (a + b)(a − b) to find 30² − 1².
37. 37.Use a² − b² = (a + b)(a − b) to find 87² − 69².
38. 38.Use (a + b)(a − b) = a² − b² to find 79 × 61.
39. 39.If a + b = 13 and ab = 22, what is a² + b²?
40. 40.Use (a − b)² = a² − 2ab + b² to find 55².

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