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.
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- 1.Use (a − b)² = a² − 2ab + b² to find 73².
- 2.Use (a − b)² = a² − 2ab + b² to find 12².
- 3.Use a² − b² = (a + b)(a − b) to find 24² − 22².
- 4.Use (a + b)(a − b) = a² − b² to find 43 × 37.
- 5.Use a² − b² = (a + b)(a − b) to find 97² − 27².
- 6.Use (a − b)² = a² − 2ab + b² to find 19².
- 7.If a + b = 3 and ab = 2, what is a² + b²?
- 8.Use (a + b)(a − b) = a² − b² to find 55 × 45.
- 9.Use (a + b)(a − b) = a² − b² to find 73 × 67.
- 10.Use a² − b² = (a + b)(a − b) to find 91² − 17².
- 11.Find the value of x² − 2xy + y² when x = 7 and y = 5.
- 12.Use (a − b)² = a² − 2ab + b² to find 74².
- 13.Use (a + b)(a − b) = a² − b² to find 84 × 76.
- 14.Use (a − b)² = a² − 2ab + b² to find 66².
- 15.Use (a + b)² = a² + 2ab + b² to find 96².
- 16.If a + b = 10 and ab = 9, what is a² + b²?
- 17.Use (a + b)² = a² + 2ab + b² to find 54².
- 18.Use (a − b)² = a² − 2ab + b² to find 94².
- 19.Use (a − b)² = a² − 2ab + b² to find 65².
- 20.Find the value of x² − 2xy + y² when x = 12 and y = 6.
- 21.Use (a + b)(a − b) = a² − b² to find 75 × 65.
- 22.Use a² − b² = (a + b)(a − b) to find 38² − 17².
- 23.Use (a + b)² = a² + 2ab + b² to find 95².
- 24.Use a² − b² = (a + b)(a − b) to find 51² − 46².
- 25.If a + b = 4 and ab = 3, what is a² + b²?
- 26.Use (a + b)(a − b) = a² − b² to find 53 × 47.
- 27.Find the value of x² − y² when x = 5 and y = 2.
- 28.Use a² − b² = (a + b)(a − b) to find 83² − 37².
- 29.Use a² − b² = (a + b)(a − b) to find 38² − 18².
- 30.Use a² − b² = (a + b)(a − b) to find 23² − 5².
- 31.Find the value of x² + 2xy + y² when x = 8 and y = 2.
- 32.Use (a − b)² = a² − 2ab + b² to find 36².
- 33.Use a² − b² = (a + b)(a − b) to find 57² − 9².
- 34.Use (a + b)² = a² + 2ab + b² to find 18².
- 35.Use (a + b)² = a² + 2ab + b² to find 63².
- 36.Use (a − b)² = a² − 2ab + b² to find 26².
- 37.Find the value of x² − y² when x = 7 and y = 1.
- 38.Use (a − b)² = a² − 2ab + b² to find 89².
- 39.Use (a + b)² = a² + 2ab + b² to find 42².
- 40.Use (a + b)² = a² + 2ab + b² to find 88².
Answer key
- 5329
- 144
- 92
- 1591
- 8680
- 361
- 5
- 2475
- 4891
- 7992
- 4
- 5476
- 6384
- 4356
- 9216
- 82
- 2916
- 8836
- 4225
- 36
- 4875
- 1155
- 9025
- 485
- 10
- 2491
- 21
- 5520
- 1120
- 504
- 100
- 1296
- 3168
- 324
- 3969
- 676
- 48
- 7921
- 1764
- 7744
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