Class 8 Maths Worksheet: Algebraic Identities

Maths worksheets lesson 61: Algebraic identities · Set 284 · 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 54² − 48².
2. 2.Use (a − b)² = a² − 2ab + b² to find 61².
3. 3.Use (a − b)² = a² − 2ab + b² to find 97².
4. 4.If a + b = 5 and ab = 6, what is a² + b²?
5. 5.Use (a − b)² = a² − 2ab + b² to find 41².
6. 6.Use (a + b)(a − b) = a² − b² to find 37 × 23.
7. 7.Use a² − b² = (a + b)(a − b) to find 69² − 42².
8. 8.Find the value of x² − y² when x = 3 and y = 1.
9. 9.If a + b = 15 and ab = 50, what is a² + b²?
10. 10.Use (a + b)(a − b) = a² − b² to find 87 × 73.
11. 11.Use (a − b)² = a² − 2ab + b² to find 12².
12. 12.Find the value of x² − y² when x = 12 and y = 7.
13. 13.Find the value of x² + 2xy + y² when x = 15 and y = 2.
14. 14.Use a² − b² = (a + b)(a − b) to find 35² − 13².
15. 15.If a + b = 3 and ab = 2, what is a² + b²?
16. 16.Use (a + b)(a − b) = a² − b² to find 88 × 72.
17. 17.If a + b = 14 and ab = 40, what is a² + b²?
18. 18.Find the value of x² + 2xy + y² when x = 9 and y = 7.
19. 19.If a − b = 4 and ab = 21, what is a² + b²?
20. 20.Use (a + b)² = a² + 2ab + b² to find 93².
21. 21.If a + b = 21 and ab = 110, what is a² + b²?
22. 22.Use (a − b)² = a² − 2ab + b² to find 77².
23. 23.If a + b = 18 and ab = 77, what is a² + b²?
24. 24.If a + b = 15 and ab = 56, what is a² + b²?
25. 25.Use (a + b)(a − b) = a² − b² to find 78 × 62.
26. 26.Use a² − b² = (a + b)(a − b) to find 61² − 22².
27. 27.If a − b = 1 and ab = 12, what is a² + b²?
28. 28.Find the value of x² − y² when x = 5 and y = 4.
29. 29.Use a² − b² = (a + b)(a − b) to find 91² − 58².
30. 30.Use (a + b)² = a² + 2ab + b² to find 98².
31. 31.Use (a − b)² = a² − 2ab + b² to find 73².
32. 32.Use (a + b)² = a² + 2ab + b² to find 89².
33. 33.Find the value of x² − y² when x = 11 and y = 6.
34. 34.Use (a + b)² = a² + 2ab + b² to find 29².
35. 35.Use (a + b)² = a² + 2ab + b² to find 58².
36. 36.If a − b = 1 and ab = 2, what is a² + b²?
37. 37.Use (a + b)² = a² + 2ab + b² to find 61².
38. 38.If a − b = 2 and ab = 3, what is a² + b²?
39. 39.Find the value of x² − 2xy + y² when x = 12 and y = 7.
40. 40.Use (a + b)² = a² + 2ab + b² to find 78².

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