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 88².
- 2.Use a² − b² = (a + b)(a − b) to find 75² − 58².
- 3.If a + b = 11 and ab = 18, what is a² + b²?
- 4.Find the value of x² − y² when x = 7 and y = 4.
- 5.Use (a + b)(a − b) = a² − b² to find 92 × 88.
- 6.If a − b = 2 and ab = 8, what is a² + b²?
- 7.If a + b = 15 and ab = 56, what is a² + b²?
- 8.Use a² − b² = (a + b)(a − b) to find 38² − 10².
- 9.Use a² − b² = (a + b)(a − b) to find 95² − 65².
- 10.Use (a + b)(a − b) = a² − b² to find 71 × 69.
- 11.Use (a + b)(a − b) = a² − b² to find 44 × 36.
- 12.Use (a + b)(a − b) = a² − b² to find 68 × 52.
- 13.Use (a − b)² = a² − 2ab + b² to find 41².
- 14.Use (a + b)² = a² + 2ab + b² to find 54².
- 15.Find the value of x² − y² when x = 4 and y = 3.
- 16.Find the value of x² − y² when x = 5 and y = 4.
- 17.Use (a − b)² = a² − 2ab + b² to find 54².
- 18.Use (a + b)² = a² + 2ab + b² to find 56².
- 19.Use (a − b)² = a² − 2ab + b² to find 38².
- 20.Use (a + b)² = a² + 2ab + b² to find 101².
- 21.If a − b = 1 and ab = 2, what is a² + b²?
- 22.Use (a + b)² = a² + 2ab + b² to find 11².
- 23.Find the value of x² − 2xy + y² when x = 11 and y = 9.
- 24.Use a² − b² = (a + b)(a − b) to find 92² − 17².
- 25.Find the value of x² − 2xy + y² when x = 14 and y = 3.
- 26.Use (a − b)² = a² − 2ab + b² to find 81².
- 27.Use (a + b)² = a² + 2ab + b² to find 103².
- 28.Use (a + b)² = a² + 2ab + b² to find 49².
- 29.Use (a + b)² = a² + 2ab + b² to find 81².
- 30.Find the value of x² − 2xy + y² when x = 3 and y = 2.
- 31.Use a² − b² = (a + b)(a − b) to find 98² − 68².
- 32.Use (a + b)(a − b) = a² − b² to find 58 × 42.
- 33.Find the value of x² − 2xy + y² when x = 14 and y = 11.
- 34.Use (a + b)(a − b) = a² − b² to find 28 × 12.
- 35.Use (a + b)² = a² + 2ab + b² to find 26².
- 36.If a − b = 2 and ab = 15, what is a² + b²?
- 37.Use (a − b)² = a² − 2ab + b² to find 36².
- 38.If a − b = 3 and ab = 18, what is a² + b²?
- 39.Use a² − b² = (a + b)(a − b) to find 77² − 66².
- 40.Use a² − b² = (a + b)(a − b) to find 95² − 25².
Answer key
- 7744
- 2261
- 85
- 33
- 8096
- 20
- 113
- 1344
- 4800
- 4899
- 1584
- 3536
- 1681
- 2916
- 7
- 9
- 2916
- 3136
- 1444
- 10201
- 5
- 121
- 4
- 8175
- 121
- 6561
- 10609
- 2401
- 6561
- 1
- 4980
- 2436
- 9
- 336
- 676
- 34
- 1296
- 45
- 1573
- 8400
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