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.If a − b = 3 and ab = 108, what is a² + b²?
- 3.Use (a + b)² = a² + 2ab + b² to find 47².
- 4.Use (a − b)² = a² − 2ab + b² to find 89².
- 5.Use (a + b)² = a² + 2ab + b² to find 83².
- 6.Use (a − b)² = a² − 2ab + b² to find 17².
- 7.Use (a − b)² = a² − 2ab + b² to find 44².
- 8.Use (a + b)(a − b) = a² − b² to find 22 × 18.
- 9.If a − b = 7 and ab = 30, what is a² + b²?
- 10.Use a² − b² = (a + b)(a − b) to find 66² − 40².
- 11.If a + b = 7 and ab = 6, what is a² + b²?
- 12.Use a² − b² = (a + b)(a − b) to find 24² − 18².
- 13.Find the value of x² − 2xy + y² when x = 10 and y = 7.
- 14.Use (a + b)² = a² + 2ab + b² to find 28².
- 15.Use (a − b)² = a² − 2ab + b² to find 93².
- 16.Find the value of x² − y² when x = 12 and y = 6.
- 17.Use (a + b)(a − b) = a² − b² to find 49 × 31.
- 18.Use (a + b)(a − b) = a² − b² to find 54 × 46.
- 19.Find the value of x² − 2xy + y² when x = 12 and y = 8.
- 20.Find the value of x² − y² when x = 12 and y = 11.
- 21.Use a² − b² = (a + b)(a − b) to find 22² − 6².
- 22.Find the value of x² + 2xy + y² when x = 11 and y = 7.
- 23.Use a² − b² = (a + b)(a − b) to find 76² − 44².
- 24.Find the value of x² + 2xy + y² when x = 10 and y = 9.
- 25.Use (a + b)(a − b) = a² − b² to find 32 × 28.
- 26.Use (a + b)² = a² + 2ab + b² to find 85².
- 27.Use a² − b² = (a + b)(a − b) to find 74² − 44².
- 28.Use (a + b)² = a² + 2ab + b² to find 31².
- 29.Find the value of x² − y² when x = 14 and y = 9.
- 30.If a + b = 11 and ab = 28, what is a² + b²?
- 31.Use (a + b)(a − b) = a² − b² to find 104 × 96.
- 32.If a − b = 1 and ab = 12, what is a² + b²?
- 33.Use (a + b)(a − b) = a² − b² to find 79 × 61.
- 34.Use a² − b² = (a + b)(a − b) to find 94² − 11².
- 35.Use (a − b)² = a² − 2ab + b² to find 98².
- 36.Use (a + b)(a − b) = a² − b² to find 74 × 66.
- 37.If a − b = 10 and ab = 11, what is a² + b²?
- 38.If a + b = 10 and ab = 16, what is a² + b²?
- 39.Use (a + b)(a − b) = a² − b² to find 84 × 76.
- 40.Use a² − b² = (a + b)(a − b) to find 29² − 7².
Answer key
- 9025
- 225
- 2209
- 7921
- 6889
- 289
- 1936
- 396
- 109
- 2756
- 37
- 252
- 9
- 784
- 8649
- 108
- 1519
- 2484
- 16
- 23
- 448
- 324
- 3840
- 361
- 896
- 7225
- 3540
- 961
- 115
- 65
- 9984
- 25
- 4819
- 8715
- 9604
- 4884
- 122
- 68
- 6384
- 792
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