Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 425 · 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 90² − 78².
2. 2.Find the value of x² + 2xy + y² when x = 10 and y = 8.
3. 3.If a + b = 15 and ab = 54, what is a² + b²?
4. 4.Use (a − b)² = a² − 2ab + b² to find 55².
5. 5.If a − b = 6 and ab = 16, what is a² + b²?
6. 6.Use (a + b)² = a² + 2ab + b² to find 58².
7. 7.Use a² − b² = (a + b)(a − b) to find 51² − 17².
8. 8.If a + b = 12 and ab = 11, what is a² + b²?
9. 9.Use (a − b)² = a² − 2ab + b² to find 19².
10. 10.Use (a − b)² = a² − 2ab + b² to find 11².
11. 11.Use (a − b)² = a² − 2ab + b² to find 92².
12. 12.If a + b = 21 and ab = 110, what is a² + b²?
13. 13.If a − b = 1 and ab = 12, what is a² + b²?
14. 14.Use (a + b)(a − b) = a² − b² to find 37 × 23.
15. 15.Use a² − b² = (a + b)(a − b) to find 42² − 2².
16. 16.Find the value of x² − y² when x = 5 and y = 4.
17. 17.Use (a + b)(a − b) = a² − b² to find 109 × 91.
18. 18.Use (a + b)² = a² + 2ab + b² to find 37².
19. 19.Find the value of x² − 2xy + y² when x = 11 and y = 4.
20. 20.Use a² − b² = (a + b)(a − b) to find 79² − 44².
21. 21.Find the value of x² + 2xy + y² when x = 8 and y = 6.
22. 22.Use (a − b)² = a² − 2ab + b² to find 38².
23. 23.Find the value of x² + 2xy + y² when x = 3 and y = 1.
24. 24.Use (a + b)² = a² + 2ab + b² to find 32².
25. 25.Use (a + b)² = a² + 2ab + b² to find 43².
26. 26.Use (a − b)² = a² − 2ab + b² to find 59².
27. 27.If a − b = 2 and ab = 15, what is a² + b²?
28. 28.Use (a − b)² = a² − 2ab + b² to find 99².
29. 29.Find the value of x² − 2xy + y² when x = 6 and y = 5.
30. 30.Use (a − b)² = a² − 2ab + b² to find 14².
31. 31.If a + b = 3 and ab = 2, what is a² + b²?
32. 32.If a + b = 17 and ab = 66, what is a² + b²?
33. 33.Use (a − b)² = a² − 2ab + b² to find 22².
34. 34.Use (a − b)² = a² − 2ab + b² to find 51².
35. 35.Use a² − b² = (a + b)(a − b) to find 40² − 22².
36. 36.Use (a − b)² = a² − 2ab + b² to find 77².
37. 37.Find the value of x² − y² when x = 6 and y = 5.
38. 38.If a + b = 10 and ab = 16, what is a² + b²?
39. 39.Use (a − b)² = a² − 2ab + b² to find 34².
40. 40.Use (a − b)² = a² − 2ab + b² to find 16².

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