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)² = a² + 2ab + b² to find 22².
- 2.Use (a + b)² = a² + 2ab + b² to find 51².
- 3.Use (a + b)² = a² + 2ab + b² to find 44².
- 4.Use (a + b)² = a² + 2ab + b² to find 93².
- 5.Use (a + b)(a − b) = a² − b² to find 91 × 89.
- 6.Use a² − b² = (a + b)(a − b) to find 64² − 29².
- 7.Use (a + b)² = a² + 2ab + b² to find 55².
- 8.If a + b = 13 and ab = 40, what is a² + b²?
- 9.Find the value of x² − 2xy + y² when x = 13 and y = 9.
- 10.Use (a + b)² = a² + 2ab + b² to find 14².
- 11.Use a² − b² = (a + b)(a − b) to find 73² − 10².
- 12.Use a² − b² = (a + b)(a − b) to find 45² − 23².
- 13.If a + b = 9 and ab = 14, what is a² + b²?
- 14.Use a² − b² = (a + b)(a − b) to find 39² − 27².
- 15.Use a² − b² = (a + b)(a − b) to find 21² − 5².
- 16.Find the value of x² − 2xy + y² when x = 7 and y = 3.
- 17.Use (a + b)² = a² + 2ab + b² to find 83².
- 18.Find the value of x² − 2xy + y² when x = 9 and y = 6.
- 19.Use (a + b)² = a² + 2ab + b² to find 106².
- 20.Find the value of x² − y² when x = 13 and y = 5.
- 21.Use a² − b² = (a + b)(a − b) to find 77² − 2².
- 22.Use (a + b)² = a² + 2ab + b² to find 86².
- 23.Use (a + b)(a − b) = a² − b² to find 109 × 91.
- 24.If a − b = 2 and ab = 24, what is a² + b²?
- 25.Use (a + b)² = a² + 2ab + b² to find 108².
- 26.If a + b = 13 and ab = 30, what is a² + b²?
- 27.Use (a − b)² = a² − 2ab + b² to find 54².
- 28.Use a² − b² = (a + b)(a − b) to find 63² − 58².
- 29.If a − b = 2 and ab = 99, what is a² + b²?
- 30.Use (a + b)(a − b) = a² − b² to find 54 × 46.
- 31.Use (a + b)² = a² + 2ab + b² to find 72².
- 32.Use a² − b² = (a + b)(a − b) to find 42² − 24².
- 33.Use (a + b)(a − b) = a² − b² to find 76 × 64.
- 34.Use (a − b)² = a² − 2ab + b² to find 53².
- 35.Use (a − b)² = a² − 2ab + b² to find 46².
- 36.Use (a + b)(a − b) = a² − b² to find 36 × 24.
- 37.Use (a − b)² = a² − 2ab + b² to find 95².
- 38.If a + b = 12 and ab = 20, what is a² + b²?
- 39.Use (a − b)² = a² − 2ab + b² to find 31².
- 40.Use (a − b)² = a² − 2ab + b² to find 33².
Answer key
- 484
- 2601
- 1936
- 8649
- 8099
- 3255
- 3025
- 89
- 16
- 196
- 5229
- 1496
- 53
- 792
- 416
- 16
- 6889
- 9
- 11236
- 144
- 5925
- 7396
- 9919
- 52
- 11664
- 109
- 2916
- 605
- 202
- 2484
- 5184
- 1188
- 4864
- 2809
- 2116
- 864
- 9025
- 104
- 961
- 1089
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets