Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 186 · 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.If a + b = 7 and ab = 6, what is a² + b²?
2. 2.Use (a + b)(a − b) = a² − b² to find 78 × 62.
3. 3.Use a² − b² = (a + b)(a − b) to find 23² − 7².
4. 4.If a + b = 16 and ab = 48, what is a² + b²?
5. 5.Use a² − b² = (a + b)(a − b) to find 80² − 66².
6. 6.If a + b = 16 and ab = 63, what is a² + b²?
7. 7.Use (a + b)(a − b) = a² − b² to find 49 × 31.
8. 8.Use (a − b)² = a² − 2ab + b² to find 38².
9. 9.Use (a + b)(a − b) = a² − b² to find 27 × 13.
10. 10.Use (a − b)² = a² − 2ab + b² to find 85².
11. 11.Find the value of x² − 2xy + y² when x = 6 and y = 5.
12. 12.Use (a + b)² = a² + 2ab + b² to find 94².
13. 13.Find the value of x² − y² when x = 8 and y = 3.
14. 14.Find the value of x² + 2xy + y² when x = 5 and y = 2.
15. 15.Find the value of x² + 2xy + y² when x = 3 and y = 2.
16. 16.If a − b = 6 and ab = 16, what is a² + b²?
17. 17.Use (a − b)² = a² − 2ab + b² to find 63².
18. 18.Find the value of x² − 2xy + y² when x = 7 and y = 6.
19. 19.Use (a + b)(a − b) = a² − b² to find 57 × 43.
20. 20.Use (a + b)² = a² + 2ab + b² to find 103².
21. 21.Find the value of x² + 2xy + y² when x = 6 and y = 2.
22. 22.Use (a + b)(a − b) = a² − b² to find 45 × 35.
23. 23.Find the value of x² − 2xy + y² when x = 5 and y = 1.
24. 24.Find the value of x² − 2xy + y² when x = 13 and y = 2.
25. 25.Use a² − b² = (a + b)(a − b) to find 57² − 56².
26. 26.Use (a + b)² = a² + 2ab + b² to find 101².
27. 27.Use (a + b)² = a² + 2ab + b² to find 99².
28. 28.If a − b = 1 and ab = 90, what is a² + b²?
29. 29.Find the value of x² + 2xy + y² when x = 13 and y = 8.
30. 30.Use (a + b)² = a² + 2ab + b² to find 69².
31. 31.Use (a + b)(a − b) = a² − b² to find 25 × 15.
32. 32.Find the value of x² − 2xy + y² when x = 8 and y = 1.
33. 33.Use (a + b)² = a² + 2ab + b² to find 48².
34. 34.Find the value of x² − 2xy + y² when x = 12 and y = 8.
35. 35.Use (a + b)² = a² + 2ab + b² to find 109².
36. 36.Find the value of x² − 2xy + y² when x = 10 and y = 6.
37. 37.Use (a + b)² = a² + 2ab + b² to find 98².
38. 38.Use a² − b² = (a + b)(a − b) to find 43² − 25².
39. 39.If a + b = 3 and ab = 2, what is a² + b²?
40. 40.Use (a − b)² = a² − 2ab + b² to find 86².

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