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 33².
- 2.Use (a + b)² = a² + 2ab + b² to find 51².
- 3.Find the value of x² − y² when x = 14 and y = 10.
- 4.Use (a + b)² = a² + 2ab + b² to find 65².
- 5.Use a² − b² = (a + b)(a − b) to find 31² − 20².
- 6.If a + b = 6 and ab = 5, what is a² + b²?
- 7.Use a² − b² = (a + b)(a − b) to find 49² − 47².
- 8.Find the value of x² − 2xy + y² when x = 3 and y = 2.
- 9.Use (a + b)² = a² + 2ab + b² to find 32².
- 10.If a + b = 19 and ab = 84, what is a² + b²?
- 11.Use a² − b² = (a + b)(a − b) to find 46² − 4².
- 12.Use (a + b)² = a² + 2ab + b² to find 53².
- 13.Use (a − b)² = a² − 2ab + b² to find 15².
- 14.Find the value of x² − 2xy + y² when x = 14 and y = 3.
- 15.If a − b = 3 and ab = 88, what is a² + b²?
- 16.Use a² − b² = (a + b)(a − b) to find 35² − 1².
- 17.Find the value of x² − 2xy + y² when x = 7 and y = 2.
- 18.Use (a − b)² = a² − 2ab + b² to find 99².
- 19.Use (a − b)² = a² − 2ab + b² to find 69².
- 20.Use (a − b)² = a² − 2ab + b² to find 53².
- 21.Use (a + b)² = a² + 2ab + b² to find 22².
- 22.If a + b = 16 and ab = 55, what is a² + b²?
- 23.Use a² − b² = (a + b)(a − b) to find 29² − 23².
- 24.Use (a − b)² = a² − 2ab + b² to find 67².
- 25.Find the value of x² − 2xy + y² when x = 13 and y = 1.
- 26.Use a² − b² = (a + b)(a − b) to find 79² − 17².
- 27.Use (a + b)² = a² + 2ab + b² to find 31².
- 28.Find the value of x² − y² when x = 14 and y = 7.
- 29.Use (a + b)² = a² + 2ab + b² to find 23².
- 30.Use (a − b)² = a² − 2ab + b² to find 72².
- 31.If a − b = 2 and ab = 3, what is a² + b²?
- 32.Use (a − b)² = a² − 2ab + b² to find 25².
- 33.Use a² − b² = (a + b)(a − b) to find 52² − 51².
- 34.If a + b = 5 and ab = 6, what is a² + b²?
- 35.Find the value of x² − 2xy + y² when x = 6 and y = 1.
- 36.Use a² − b² = (a + b)(a − b) to find 85² − 34².
- 37.If a + b = 12 and ab = 27, what is a² + b²?
- 38.If a − b = 2 and ab = 15, what is a² + b²?
- 39.Use (a + b)² = a² + 2ab + b² to find 73².
- 40.If a + b = 11 and ab = 30, what is a² + b²?
Answer key
- 1089
- 2601
- 96
- 4225
- 561
- 26
- 192
- 1
- 1024
- 193
- 2100
- 2809
- 225
- 121
- 185
- 1224
- 25
- 9801
- 4761
- 2809
- 484
- 146
- 312
- 4489
- 144
- 5952
- 961
- 147
- 529
- 5184
- 10
- 625
- 103
- 13
- 25
- 6069
- 90
- 34
- 5329
- 61
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