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 107 × 93.
- 2.Use (a + b)(a − b) = a² − b² to find 64 × 56.
- 3.Use (a + b)² = a² + 2ab + b² to find 66².
- 4.If a − b = 2 and ab = 3, what is a² + b²?
- 5.Use (a + b)(a − b) = a² − b² to find 31 × 29.
- 6.Find the value of x² − y² when x = 7 and y = 1.
- 7.Use (a + b)² = a² + 2ab + b² to find 21².
- 8.If a + b = 15 and ab = 50, what is a² + b²?
- 9.Find the value of x² − 2xy + y² when x = 5 and y = 3.
- 10.Use (a + b)² = a² + 2ab + b² to find 57².
- 11.Use (a − b)² = a² − 2ab + b² to find 19².
- 12.Use (a − b)² = a² − 2ab + b² to find 16².
- 13.Use (a + b)² = a² + 2ab + b² to find 93².
- 14.If a − b = 6 and ab = 55, what is a² + b²?
- 15.Find the value of x² − 2xy + y² when x = 5 and y = 1.
- 16.Use a² − b² = (a + b)(a − b) to find 57² − 51².
- 17.Find the value of x² + 2xy + y² when x = 13 and y = 12.
- 18.Use a² − b² = (a + b)(a − b) to find 83² − 43².
- 19.Use (a + b)(a − b) = a² − b² to find 95 × 85.
- 20.Find the value of x² − 2xy + y² when x = 13 and y = 1.
- 21.Find the value of x² − 2xy + y² when x = 13 and y = 4.
- 22.Use (a − b)² = a² − 2ab + b² to find 32².
- 23.Use (a − b)² = a² − 2ab + b² to find 66².
- 24.Use a² − b² = (a + b)(a − b) to find 39² − 12².
- 25.Use (a + b)² = a² + 2ab + b² to find 25².
- 26.Use a² − b² = (a + b)(a − b) to find 25² − 19².
- 27.Find the value of x² + 2xy + y² when x = 3 and y = 2.
- 28.Use a² − b² = (a + b)(a − b) to find 26² − 1².
- 29.Use (a − b)² = a² − 2ab + b² to find 52².
- 30.Use (a + b)(a − b) = a² − b² to find 94 × 86.
- 31.Use (a − b)² = a² − 2ab + b² to find 21².
- 32.Use a² − b² = (a + b)(a − b) to find 62² − 12².
- 33.Use (a + b)² = a² + 2ab + b² to find 65².
- 34.Use a² − b² = (a + b)(a − b) to find 26² − 23².
- 35.Use (a + b)² = a² + 2ab + b² to find 83².
- 36.If a + b = 7 and ab = 12, what is a² + b²?
- 37.Find the value of x² − y² when x = 15 and y = 9.
- 38.Use a² − b² = (a + b)(a − b) to find 51² − 20².
- 39.Use (a + b)(a − b) = a² − b² to find 24 × 16.
- 40.Find the value of x² − y² when x = 10 and y = 3.
Answer key
- 9951
- 3584
- 4356
- 10
- 899
- 48
- 441
- 125
- 4
- 3249
- 361
- 256
- 8649
- 146
- 16
- 648
- 625
- 5040
- 8075
- 144
- 81
- 1024
- 4356
- 1377
- 625
- 264
- 25
- 675
- 2704
- 8084
- 441
- 3700
- 4225
- 147
- 6889
- 25
- 144
- 2201
- 384
- 91
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