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 48².
- 2.Use (a + b)(a − b) = a² − b² to find 44 × 36.
- 3.Use (a − b)² = a² − 2ab + b² to find 27².
- 4.Use (a + b)² = a² + 2ab + b² to find 37².
- 5.Use (a + b)² = a² + 2ab + b² to find 66².
- 6.Use (a + b)² = a² + 2ab + b² to find 11².
- 7.Use a² − b² = (a + b)(a − b) to find 75² − 31².
- 8.Use (a + b)(a − b) = a² − b² to find 27 × 13.
- 9.If a − b = 9 and ab = 22, what is a² + b²?
- 10.Use (a + b)(a − b) = a² − b² to find 39 × 21.
- 11.Use (a − b)² = a² − 2ab + b² to find 61².
- 12.Use (a + b)² = a² + 2ab + b² to find 22².
- 13.Use (a − b)² = a² − 2ab + b² to find 68².
- 14.Use (a − b)² = a² − 2ab + b² to find 23².
- 15.Use (a + b)² = a² + 2ab + b² to find 53².
- 16.If a − b = 1 and ab = 2, what is a² + b²?
- 17.Use (a + b)(a − b) = a² − b² to find 97 × 83.
- 18.Use a² − b² = (a + b)(a − b) to find 31² − 12².
- 19.Use a² − b² = (a + b)(a − b) to find 64² − 11².
- 20.Use (a − b)² = a² − 2ab + b² to find 19².
- 21.If a − b = 3 and ab = 70, what is a² + b²?
- 22.Use (a + b)(a − b) = a² − b² to find 73 × 67.
- 23.Use (a − b)² = a² − 2ab + b² to find 53².
- 24.Find the value of x² + 2xy + y² when x = 5 and y = 3.
- 25.If a − b = 5 and ab = 84, what is a² + b²?
- 26.Use a² − b² = (a + b)(a − b) to find 37² − 14².
- 27.Use (a + b)(a − b) = a² − b² to find 31 × 29.
- 28.Use (a + b)² = a² + 2ab + b² to find 52².
- 29.Use (a + b)² = a² + 2ab + b² to find 106².
- 30.Use a² − b² = (a + b)(a − b) to find 55² − 36².
- 31.Use a² − b² = (a + b)(a − b) to find 80² − 26².
- 32.Use (a − b)² = a² − 2ab + b² to find 57².
- 33.Find the value of x² − 2xy + y² when x = 9 and y = 3.
- 34.If a + b = 15 and ab = 54, what is a² + b²?
- 35.Use (a + b)(a − b) = a² − b² to find 47 × 33.
- 36.Find the value of x² + 2xy + y² when x = 15 and y = 13.
- 37.Use (a + b)² = a² + 2ab + b² to find 32².
- 38.Use (a − b)² = a² − 2ab + b² to find 76².
- 39.If a − b = 4 and ab = 5, what is a² + b²?
- 40.Use a² − b² = (a + b)(a − b) to find 91² − 41².
Answer key
- 2304
- 1584
- 729
- 1369
- 4356
- 121
- 4664
- 351
- 125
- 819
- 3721
- 484
- 4624
- 529
- 2809
- 5
- 8051
- 817
- 3975
- 361
- 149
- 4891
- 2809
- 64
- 193
- 1173
- 899
- 2704
- 11236
- 1729
- 5724
- 3249
- 36
- 117
- 1551
- 784
- 1024
- 5776
- 26
- 6600
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