Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 462 · 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 28².
2. 2.Use (a + b)(a − b) = a² − b² to find 36 × 24.
3. 3.If a + b = 12 and ab = 11, what is a² + b²?
4. 4.Use (a − b)² = a² − 2ab + b² to find 63².
5. 5.Find the value of x² − 2xy + y² when x = 15 and y = 8.
6. 6.Use (a + b)² = a² + 2ab + b² to find 48².
7. 7.If a − b = 1 and ab = 12, what is a² + b²?
8. 8.Find the value of x² − 2xy + y² when x = 9 and y = 5.
9. 9.Find the value of x² + 2xy + y² when x = 15 and y = 5.
10. 10.Use (a + b)(a − b) = a² − b² to find 108 × 92.
11. 11.Use (a + b)² = a² + 2ab + b² to find 25².
12. 12.Use a² − b² = (a + b)(a − b) to find 59² − 16².
13. 13.Find the value of x² + 2xy + y² when x = 9 and y = 8.
14. 14.Find the value of x² + 2xy + y² when x = 6 and y = 5.
15. 15.Use (a + b)(a − b) = a² − b² to find 96 × 84.
16. 16.Use (a − b)² = a² − 2ab + b² to find 91².
17. 17.Use (a + b)² = a² + 2ab + b² to find 44².
18. 18.Use (a − b)² = a² − 2ab + b² to find 65².
19. 19.Use (a − b)² = a² − 2ab + b² to find 99².
20. 20.Use a² − b² = (a + b)(a − b) to find 63² − 3².
21. 21.Use (a − b)² = a² − 2ab + b² to find 15².
22. 22.Find the value of x² − y² when x = 15 and y = 1.
23. 23.Use (a + b)(a − b) = a² − b² to find 47 × 33.
24. 24.Find the value of x² + 2xy + y² when x = 15 and y = 9.
25. 25.Find the value of x² − 2xy + y² when x = 9 and y = 4.
26. 26.Use (a + b)² = a² + 2ab + b² to find 86².
27. 27.Find the value of x² − 2xy + y² when x = 7 and y = 6.
28. 28.Use (a + b)(a − b) = a² − b² to find 63 × 57.
29. 29.Use (a + b)(a − b) = a² − b² to find 58 × 42.
30. 30.If a + b = 13 and ab = 30, what is a² + b²?
31. 31.If a − b = 8 and ab = 9, what is a² + b²?
32. 32.If a − b = 3 and ab = 18, what is a² + b²?
33. 33.If a + b = 4 and ab = 3, what is a² + b²?
34. 34.Use (a − b)² = a² − 2ab + b² to find 94².
35. 35.Use (a + b)² = a² + 2ab + b² to find 61².
36. 36.If a + b = 15 and ab = 56, what is a² + b²?
37. 37.If a − b = 6 and ab = 40, what is a² + b²?
38. 38.Use (a − b)² = a² − 2ab + b² to find 37².
39. 39.Use (a + b)² = a² + 2ab + b² to find 102².
40. 40.Use (a + b)(a − b) = a² − b² to find 107 × 93.

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