Class 8 Maths Worksheet: Algebraic Identities
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.
NameDateTime takenScore ___ / 40
- 1.Use (a + b)(a − b) = a² − b² to find 91 × 89.
- 2.Use (a − b)² = a² − 2ab + b² to find 53².
- 3.Use (a + b)(a − b) = a² − b² to find 105 × 95.
- 4.If a + b = 14 and ab = 33, what is a² + b²?
- 5.Use (a − b)² = a² − 2ab + b² to find 57².
- 6.Use (a + b)(a − b) = a² − b² to find 69 × 51.
- 7.Use (a − b)² = a² − 2ab + b² to find 71².
- 8.Use (a + b)(a − b) = a² − b² to find 34 × 26.
- 9.Use (a + b)(a − b) = a² − b² to find 61 × 59.
- 10.If a − b = 1 and ab = 2, what is a² + b²?
- 11.Use a² − b² = (a + b)(a − b) to find 63² − 25².
- 12.Use a² − b² = (a + b)(a − b) to find 33² − 10².
- 13.Find the value of x² − y² when x = 15 and y = 8.
- 14.Use (a + b)² = a² + 2ab + b² to find 22².
- 15.If a + b = 6 and ab = 5, what is a² + b²?
- 16.Use a² − b² = (a + b)(a − b) to find 97² − 80².
- 17.Use (a + b)² = a² + 2ab + b² to find 105².
- 18.Find the value of x² − 2xy + y² when x = 3 and y = 1.
- 19.Use (a − b)² = a² − 2ab + b² to find 35².
- 20.If a − b = 4 and ab = 5, what is a² + b²?
- 21.Use (a + b)(a − b) = a² − b² to find 29 × 11.
- 22.Find the value of x² − y² when x = 14 and y = 12.
- 23.Use a² − b² = (a + b)(a − b) to find 85² − 38².
- 24.If a + b = 13 and ab = 40, what is a² + b²?
- 25.Use (a + b)(a − b) = a² − b² to find 95 × 85.
- 26.If a + b = 4 and ab = 3, what is a² + b²?
- 27.Use (a + b)² = a² + 2ab + b² to find 52².
- 28.Use (a − b)² = a² − 2ab + b² to find 67².
- 29.Use a² − b² = (a + b)(a − b) to find 39² − 14².
- 30.Use (a + b)² = a² + 2ab + b² to find 69².
- 31.Use (a + b)(a − b) = a² − b² to find 43 × 37.
- 32.Find the value of x² + 2xy + y² when x = 4 and y = 2.
- 33.Use (a + b)² = a² + 2ab + b² to find 32².
- 34.Use (a − b)² = a² − 2ab + b² to find 51².
- 35.Use (a + b)² = a² + 2ab + b² to find 63².
- 36.Use a² − b² = (a + b)(a − b) to find 83² − 47².
- 37.Use (a − b)² = a² − 2ab + b² to find 15².
- 38.Find the value of x² − 2xy + y² when x = 15 and y = 10.
- 39.Use (a + b)(a − b) = a² − b² to find 82 × 78.
- 40.Use (a + b)(a − b) = a² − b² to find 94 × 86.
Answer key
- 8099
- 2809
- 9975
- 130
- 3249
- 3519
- 5041
- 884
- 3599
- 5
- 3344
- 989
- 161
- 484
- 26
- 3009
- 11025
- 4
- 1225
- 26
- 319
- 52
- 5781
- 89
- 8075
- 10
- 2704
- 4489
- 1325
- 4761
- 1591
- 36
- 1024
- 2601
- 3969
- 4680
- 225
- 25
- 6396
- 8084
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets