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)(a − b) = a² − b² to find 44 × 36.
- 2.Use (a + b)(a − b) = a² − b² to find 73 × 67.
- 3.Use a² − b² = (a + b)(a − b) to find 37² − 7².
- 4.Use (a − b)² = a² − 2ab + b² to find 96².
- 5.Use (a + b)² = a² + 2ab + b² to find 28².
- 6.If a − b = 1 and ab = 2, what is a² + b²?
- 7.Use (a − b)² = a² − 2ab + b² to find 98².
- 8.Use a² − b² = (a + b)(a − b) to find 81² − 31².
- 9.Find the value of x² − 2xy + y² when x = 14 and y = 1.
- 10.Use (a − b)² = a² − 2ab + b² to find 63².
- 11.Use (a + b)(a − b) = a² − b² to find 24 × 16.
- 12.Use (a + b)(a − b) = a² − b² to find 59 × 41.
- 13.If a − b = 1 and ab = 20, what is a² + b²?
- 14.If a + b = 6 and ab = 5, what is a² + b²?
- 15.Use (a − b)² = a² − 2ab + b² to find 59².
- 16.If a − b = 5 and ab = 14, what is a² + b²?
- 17.If a − b = 4 and ab = 96, what is a² + b²?
- 18.Use (a + b)(a − b) = a² − b² to find 72 × 68.
- 19.Find the value of x² − 2xy + y² when x = 3 and y = 2.
- 20.Find the value of x² − 2xy + y² when x = 8 and y = 6.
- 21.Use (a − b)² = a² − 2ab + b² to find 52².
- 22.Find the value of x² + 2xy + y² when x = 12 and y = 9.
- 23.Use (a + b)² = a² + 2ab + b² to find 58².
- 24.Find the value of x² − 2xy + y² when x = 9 and y = 3.
- 25.Use (a + b)(a − b) = a² − b² to find 36 × 24.
- 26.Find the value of x² + 2xy + y² when x = 11 and y = 8.
- 27.Find the value of x² − y² when x = 14 and y = 7.
- 28.If a + b = 15 and ab = 56, what is a² + b²?
- 29.Use (a + b)(a − b) = a² − b² to find 107 × 93.
- 30.If a − b = 6 and ab = 27, what is a² + b²?
- 31.Use (a + b)² = a² + 2ab + b² to find 37².
- 32.Find the value of x² − y² when x = 7 and y = 4.
- 33.Use (a + b)² = a² + 2ab + b² to find 18².
- 34.Find the value of x² − 2xy + y² when x = 7 and y = 4.
- 35.Find the value of x² − y² when x = 9 and y = 7.
- 36.Use a² − b² = (a + b)(a − b) to find 64² − 17².
- 37.Use a² − b² = (a + b)(a − b) to find 80² − 18².
- 38.Use a² − b² = (a + b)(a − b) to find 28² − 15².
- 39.Use (a − b)² = a² − 2ab + b² to find 88².
- 40.If a − b = 2 and ab = 120, what is a² + b²?
Answer key
- 1584
- 4891
- 1320
- 9216
- 784
- 5
- 9604
- 5600
- 169
- 3969
- 384
- 2419
- 41
- 26
- 3481
- 53
- 208
- 4896
- 1
- 4
- 2704
- 441
- 3364
- 36
- 864
- 361
- 147
- 113
- 9951
- 90
- 1369
- 33
- 324
- 9
- 32
- 3807
- 6076
- 559
- 7744
- 244
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