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 95².
- 2.Use (a + b)² = a² + 2ab + b² to find 94².
- 3.Use a² − b² = (a + b)(a − b) to find 64² − 21².
- 4.If a − b = 2 and ab = 8, what is a² + b²?
- 5.Use (a + b)² = a² + 2ab + b² to find 61².
- 6.Use (a − b)² = a² − 2ab + b² to find 14².
- 7.Use (a − b)² = a² − 2ab + b² to find 19².
- 8.Use (a − b)² = a² − 2ab + b² to find 45².
- 9.Use a² − b² = (a + b)(a − b) to find 34² − 9².
- 10.Find the value of x² − 2xy + y² when x = 7 and y = 3.
- 11.Use (a − b)² = a² − 2ab + b² to find 66².
- 12.Use a² − b² = (a + b)(a − b) to find 53² − 7².
- 13.Find the value of x² − 2xy + y² when x = 9 and y = 6.
- 14.Use (a − b)² = a² − 2ab + b² to find 33².
- 15.If a − b = 8 and ab = 9, what is a² + b²?
- 16.Find the value of x² − 2xy + y² when x = 9 and y = 1.
- 17.Find the value of x² − y² when x = 4 and y = 2.
- 18.Use (a − b)² = a² − 2ab + b² to find 76².
- 19.Use a² − b² = (a + b)(a − b) to find 91² − 37².
- 20.Use (a + b)(a − b) = a² − b² to find 23 × 17.
- 21.If a − b = 3 and ab = 4, what is a² + b²?
- 22.Use (a + b)² = a² + 2ab + b² to find 76².
- 23.Use (a − b)² = a² − 2ab + b² to find 72².
- 24.Use a² − b² = (a + b)(a − b) to find 54² − 31².
- 25.Use (a − b)² = a² − 2ab + b² to find 54².
- 26.Use (a + b)² = a² + 2ab + b² to find 44².
- 27.Use (a + b)(a − b) = a² − b² to find 29 × 11.
- 28.Use (a − b)² = a² − 2ab + b² to find 24².
- 29.Find the value of x² + 2xy + y² when x = 7 and y = 4.
- 30.If a − b = 8 and ab = 48, what is a² + b²?
- 31.Use (a + b)² = a² + 2ab + b² to find 82².
- 32.Use (a + b)(a − b) = a² − b² to find 27 × 13.
- 33.Use (a + b)(a − b) = a² − b² to find 84 × 76.
- 34.Find the value of x² + 2xy + y² when x = 6 and y = 4.
- 35.Find the value of x² + 2xy + y² when x = 14 and y = 11.
- 36.Use (a + b)² = a² + 2ab + b² to find 68².
- 37.Find the value of x² + 2xy + y² when x = 13 and y = 7.
- 38.If a + b = 3 and ab = 2, what is a² + b²?
- 39.Use (a − b)² = a² − 2ab + b² to find 75².
- 40.Find the value of x² + 2xy + y² when x = 11 and y = 8.
Answer key
- 9025
- 8836
- 3655
- 20
- 3721
- 196
- 361
- 2025
- 1075
- 16
- 4356
- 2760
- 9
- 1089
- 82
- 64
- 12
- 5776
- 6912
- 391
- 17
- 5776
- 5184
- 1955
- 2916
- 1936
- 319
- 576
- 121
- 160
- 6724
- 351
- 6384
- 100
- 625
- 4624
- 400
- 5
- 5625
- 361
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