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.
NameDateTime takenScore ___ / 40
- 1.Use (a − b)² = a² − 2ab + b² to find 92².
- 2.If a + b = 3 and ab = 2, what is a² + b²?
- 3.Use a² − b² = (a + b)(a − b) to find 96² − 24².
- 4.Find the value of x² − y² when x = 9 and y = 5.
- 5.Use (a + b)(a − b) = a² − b² to find 74 × 66.
- 6.If a + b = 5 and ab = 6, what is a² + b²?
- 7.Find the value of x² − 2xy + y² when x = 4 and y = 3.
- 8.Find the value of x² − y² when x = 10 and y = 1.
- 9.Use (a − b)² = a² − 2ab + b² to find 73².
- 10.Use (a + b)² = a² + 2ab + b² to find 84².
- 11.Find the value of x² + 2xy + y² when x = 6 and y = 5.
- 12.Use (a − b)² = a² − 2ab + b² to find 64².
- 13.Use (a + b)² = a² + 2ab + b² to find 59².
- 14.Use (a + b)² = a² + 2ab + b² to find 85².
- 15.Use (a + b)² = a² + 2ab + b² to find 108².
- 16.Use (a − b)² = a² − 2ab + b² to find 83².
- 17.Use (a + b)(a − b) = a² − b² to find 69 × 51.
- 18.Use (a + b)(a − b) = a² − b² to find 51 × 49.
- 19.Find the value of x² + 2xy + y² when x = 11 and y = 6.
- 20.Use a² − b² = (a + b)(a − b) to find 43² − 32².
- 21.Use (a − b)² = a² − 2ab + b² to find 97².
- 22.Use (a − b)² = a² − 2ab + b² to find 32².
- 23.Use (a − b)² = a² − 2ab + b² to find 24².
- 24.Use a² − b² = (a + b)(a − b) to find 45² − 15².
- 25.Use (a + b)(a − b) = a² − b² to find 53 × 47.
- 26.Use a² − b² = (a + b)(a − b) to find 33² − 8².
- 27.Use (a + b)(a − b) = a² − b² to find 103 × 97.
- 28.Find the value of x² − y² when x = 12 and y = 5.
- 29.Use (a − b)² = a² − 2ab + b² to find 53².
- 30.If a + b = 12 and ab = 20, what is a² + b²?
- 31.Use a² − b² = (a + b)(a − b) to find 58² − 20².
- 32.Use (a − b)² = a² − 2ab + b² to find 88².
- 33.Use (a − b)² = a² − 2ab + b² to find 19².
- 34.Find the value of x² + 2xy + y² when x = 4 and y = 3.
- 35.If a − b = 3 and ab = 28, what is a² + b²?
- 36.Use (a + b)(a − b) = a² − b² to find 102 × 98.
- 37.Use (a + b)² = a² + 2ab + b² to find 103².
- 38.Use a² − b² = (a + b)(a − b) to find 26² − 21².
- 39.Use a² − b² = (a + b)(a − b) to find 77² − 8².
- 40.If a − b = 2 and ab = 3, what is a² + b²?
Answer key
- 8464
- 5
- 8640
- 56
- 4884
- 13
- 1
- 99
- 5329
- 7056
- 121
- 4096
- 3481
- 7225
- 11664
- 6889
- 3519
- 2499
- 289
- 825
- 9409
- 1024
- 576
- 1800
- 2491
- 1025
- 9991
- 119
- 2809
- 104
- 2964
- 7744
- 361
- 49
- 65
- 9996
- 10609
- 235
- 5865
- 10
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