Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 51 · 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 87² − 7².
2. 2.If a + b = 19 and ab = 90, what is a² + b²?
3. 3.Use (a − b)² = a² − 2ab + b² to find 31².
4. 4.Find the value of x² − y² when x = 4 and y = 3.
5. 5.Use (a + b)² = a² + 2ab + b² to find 53².
6. 6.Use (a − b)² = a² − 2ab + b² to find 51².
7. 7.If a − b = 2 and ab = 3, what is a² + b²?
8. 8.Use a² − b² = (a + b)(a − b) to find 50² − 5².
9. 9.Use (a − b)² = a² − 2ab + b² to find 75².
10. 10.Use (a − b)² = a² − 2ab + b² to find 45².
11. 11.Use (a + b)(a − b) = a² − b² to find 21 × 19.
12. 12.Find the value of x² − 2xy + y² when x = 7 and y = 6.
13. 13.Use (a − b)² = a² − 2ab + b² to find 11².
14. 14.If a − b = 1 and ab = 30, what is a² + b²?
15. 15.Use a² − b² = (a + b)(a − b) to find 92² − 7².
16. 16.Use (a + b)² = a² + 2ab + b² to find 12².
17. 17.Find the value of x² − 2xy + y² when x = 13 and y = 5.
18. 18.Find the value of x² − 2xy + y² when x = 11 and y = 9.
19. 19.Use (a + b)(a − b) = a² − b² to find 93 × 87.
20. 20.Find the value of x² + 2xy + y² when x = 8 and y = 3.
21. 21.Use a² − b² = (a + b)(a − b) to find 27² − 21².
22. 22.Find the value of x² − y² when x = 8 and y = 1.
23. 23.Use (a + b)² = a² + 2ab + b² to find 78².
24. 24.Find the value of x² − y² when x = 6 and y = 3.
25. 25.Use (a + b)² = a² + 2ab + b² to find 41².
26. 26.Use (a − b)² = a² − 2ab + b² to find 95².
27. 27.Use a² − b² = (a + b)(a − b) to find 76² − 9².
28. 28.Use (a + b)² = a² + 2ab + b² to find 74².
29. 29.Use a² − b² = (a + b)(a − b) to find 81² − 54².
30. 30.Use a² − b² = (a + b)(a − b) to find 43² − 20².
31. 31.Use a² − b² = (a + b)(a − b) to find 53² − 47².
32. 32.Use (a + b)² = a² + 2ab + b² to find 71².
33. 33.Use a² − b² = (a + b)(a − b) to find 86² − 51².
34. 34.If a − b = 5 and ab = 36, what is a² + b²?
35. 35.Use (a + b)(a − b) = a² − b² to find 45 × 35.
36. 36.Use a² − b² = (a + b)(a − b) to find 79² − 60².
37. 37.Use (a + b)(a − b) = a² − b² to find 51 × 49.
38. 38.Find the value of x² − 2xy + y² when x = 4 and y = 1.
39. 39.Use (a − b)² = a² − 2ab + b² to find 53².
40. 40.Use a² − b² = (a + b)(a − b) to find 37² − 9².

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