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 a² − b² = (a + b)(a − b) to find 41² − 32².
- 2.Find the value of x² − y² when x = 15 and y = 2.
- 3.Use (a + b)² = a² + 2ab + b² to find 88².
- 4.If a + b = 13 and ab = 22, what is a² + b²?
- 5.Use (a + b)² = a² + 2ab + b² to find 42².
- 6.If a − b = 3 and ab = 108, what is a² + b²?
- 7.Use a² − b² = (a + b)(a − b) to find 93² − 74².
- 8.Use (a + b)(a − b) = a² − b² to find 104 × 96.
- 9.Use a² − b² = (a + b)(a − b) to find 83² − 59².
- 10.Use (a + b)² = a² + 2ab + b² to find 58².
- 11.Use (a + b)² = a² + 2ab + b² to find 97².
- 12.Use (a + b)² = a² + 2ab + b² to find 17².
- 13.Use (a + b)² = a² + 2ab + b² to find 31².
- 14.Use (a + b)² = a² + 2ab + b² to find 96².
- 15.Use (a − b)² = a² − 2ab + b² to find 38².
- 16.Use (a + b)² = a² + 2ab + b² to find 67².
- 17.Use (a + b)(a − b) = a² − b² to find 86 × 74.
- 18.Use (a + b)² = a² + 2ab + b² to find 22².
- 19.Use (a − b)² = a² − 2ab + b² to find 43².
- 20.Use (a + b)² = a² + 2ab + b² to find 86².
- 21.Use a² − b² = (a + b)(a − b) to find 28² − 11².
- 22.Find the value of x² + 2xy + y² when x = 4 and y = 1.
- 23.Use a² − b² = (a + b)(a − b) to find 25² − 14².
- 24.Use (a − b)² = a² − 2ab + b² to find 82².
- 25.Use (a + b)(a − b) = a² − b² to find 24 × 16.
- 26.Use (a − b)² = a² − 2ab + b² to find 64².
- 27.Use (a − b)² = a² − 2ab + b² to find 35².
- 28.Use (a − b)² = a² − 2ab + b² to find 88².
- 29.Use (a − b)² = a² − 2ab + b² to find 51².
- 30.Find the value of x² + 2xy + y² when x = 14 and y = 3.
- 31.Use a² − b² = (a + b)(a − b) to find 92² − 46².
- 32.Use (a − b)² = a² − 2ab + b² to find 56².
- 33.Use a² − b² = (a + b)(a − b) to find 53² − 43².
- 34.Use a² − b² = (a + b)(a − b) to find 47² − 39².
- 35.If a + b = 14 and ab = 40, what is a² + b²?
- 36.If a − b = 1 and ab = 2, what is a² + b²?
- 37.Use (a − b)² = a² − 2ab + b² to find 24².
- 38.Use a² − b² = (a + b)(a − b) to find 32² − 22².
- 39.If a − b = 2 and ab = 120, what is a² + b²?
- 40.Find the value of x² + 2xy + y² when x = 7 and y = 1.
Answer key
- 657
- 221
- 7744
- 125
- 1764
- 225
- 3173
- 9984
- 3408
- 3364
- 9409
- 289
- 961
- 9216
- 1444
- 4489
- 6364
- 484
- 1849
- 7396
- 663
- 25
- 429
- 6724
- 384
- 4096
- 1225
- 7744
- 2601
- 289
- 6348
- 3136
- 960
- 688
- 116
- 5
- 576
- 540
- 244
- 64
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets