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 59².
- 2.If a + b = 6 and ab = 8, what is a² + b²?
- 3.Use a² − b² = (a + b)(a − b) to find 35² − 27².
- 4.Use (a + b)(a − b) = a² − b² to find 102 × 98.
- 5.Use (a + b)(a − b) = a² − b² to find 78 × 62.
- 6.Use a² − b² = (a + b)(a − b) to find 50² − 32².
- 7.Use (a + b)² = a² + 2ab + b² to find 78².
- 8.Find the value of x² − y² when x = 5 and y = 4.
- 9.If a + b = 5 and ab = 4, what is a² + b²?
- 10.Use (a − b)² = a² − 2ab + b² to find 52².
- 11.Use (a + b)(a − b) = a² − b² to find 103 × 97.
- 12.Find the value of x² − 2xy + y² when x = 4 and y = 3.
- 13.Use (a + b)(a − b) = a² − b² to find 62 × 58.
- 14.Use (a − b)² = a² − 2ab + b² to find 31².
- 15.If a − b = 5 and ab = 6, what is a² + b²?
- 16.Use (a + b)² = a² + 2ab + b² to find 96².
- 17.Find the value of x² + 2xy + y² when x = 4 and y = 3.
- 18.Use (a − b)² = a² − 2ab + b² to find 86².
- 19.Find the value of x² − 2xy + y² when x = 4 and y = 2.
- 20.Find the value of x² − y² when x = 12 and y = 11.
- 21.Use (a − b)² = a² − 2ab + b² to find 16².
- 22.Use (a + b)² = a² + 2ab + b² to find 28².
- 23.Use (a − b)² = a² − 2ab + b² to find 85².
- 24.If a + b = 7 and ab = 6, what is a² + b²?
- 25.Use (a + b)² = a² + 2ab + b² to find 22².
- 26.Use (a + b)(a − b) = a² − b² to find 27 × 13.
- 27.If a − b = 5 and ab = 24, what is a² + b²?
- 28.Use a² − b² = (a + b)(a − b) to find 33² − 8².
- 29.Use (a − b)² = a² − 2ab + b² to find 92².
- 30.Use a² − b² = (a + b)(a − b) to find 41² − 29².
- 31.Use (a − b)² = a² − 2ab + b² to find 61².
- 32.Use (a + b)² = a² + 2ab + b² to find 68².
- 33.Find the value of x² − y² when x = 12 and y = 8.
- 34.Use (a − b)² = a² − 2ab + b² to find 37².
- 35.Use (a − b)² = a² − 2ab + b² to find 39².
- 36.If a + b = 5 and ab = 6, what is a² + b²?
- 37.If a − b = 2 and ab = 8, what is a² + b²?
- 38.Use (a + b)² = a² + 2ab + b² to find 54².
- 39.Use a² − b² = (a + b)(a − b) to find 78² − 35².
- 40.Use (a + b)² = a² + 2ab + b² to find 67².
Answer key
- 3481
- 20
- 496
- 9996
- 4836
- 1476
- 6084
- 9
- 17
- 2704
- 9991
- 1
- 3596
- 961
- 37
- 9216
- 49
- 7396
- 4
- 23
- 256
- 784
- 7225
- 37
- 484
- 351
- 73
- 1025
- 8464
- 840
- 3721
- 4624
- 80
- 1369
- 1521
- 13
- 20
- 2916
- 4859
- 4489
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