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 66 × 54.
- 2.Use (a + b)(a − b) = a² − b² to find 73 × 67.
- 3.Find the value of x² − y² when x = 11 and y = 8.
- 4.Use a² − b² = (a + b)(a − b) to find 54² − 15².
- 5.Find the value of x² − y² when x = 11 and y = 1.
- 6.If a − b = 3 and ab = 108, what is a² + b²?
- 7.Find the value of x² − y² when x = 13 and y = 2.
- 8.Use (a + b)(a − b) = a² − b² to find 56 × 44.
- 9.Use a² − b² = (a + b)(a − b) to find 91² − 35².
- 10.Use (a − b)² = a² − 2ab + b² to find 56².
- 11.Find the value of x² − 2xy + y² when x = 15 and y = 13.
- 12.Find the value of x² − y² when x = 13 and y = 10.
- 13.Use (a + b)(a − b) = a² − b² to find 71 × 69.
- 14.Find the value of x² − 2xy + y² when x = 12 and y = 5.
- 15.Use (a + b)(a − b) = a² − b² to find 25 × 15.
- 16.Use (a − b)² = a² − 2ab + b² to find 71².
- 17.Use (a + b)(a − b) = a² − b² to find 83 × 77.
- 18.Find the value of x² − 2xy + y² when x = 3 and y = 2.
- 19.Use a² − b² = (a + b)(a − b) to find 40² − 23².
- 20.Use (a + b)² = a² + 2ab + b² to find 13².
- 21.Find the value of x² − 2xy + y² when x = 5 and y = 4.
- 22.Use a² − b² = (a + b)(a − b) to find 24² − 5².
- 23.Use (a + b)² = a² + 2ab + b² to find 49².
- 24.Use (a − b)² = a² − 2ab + b² to find 46².
- 25.If a + b = 4 and ab = 3, what is a² + b²?
- 26.Use (a + b)² = a² + 2ab + b² to find 19².
- 27.Use a² − b² = (a + b)(a − b) to find 93² − 59².
- 28.Find the value of x² − y² when x = 12 and y = 7.
- 29.Use (a + b)² = a² + 2ab + b² to find 25².
- 30.Use (a − b)² = a² − 2ab + b² to find 23².
- 31.If a − b = 1 and ab = 20, what is a² + b²?
- 32.Use a² − b² = (a + b)(a − b) to find 44² − 6².
- 33.Use a² − b² = (a + b)(a − b) to find 25² − 7².
- 34.Use a² − b² = (a + b)(a − b) to find 76² − 70².
- 35.Use a² − b² = (a + b)(a − b) to find 28² − 24².
- 36.Use a² − b² = (a + b)(a − b) to find 71² − 62².
- 37.Find the value of x² − y² when x = 9 and y = 2.
- 38.Use (a − b)² = a² − 2ab + b² to find 64².
- 39.Use (a + b)(a − b) = a² − b² to find 102 × 98.
- 40.Use (a + b)² = a² + 2ab + b² to find 41².
Answer key
- 3564
- 4891
- 57
- 2691
- 120
- 225
- 165
- 2464
- 7056
- 3136
- 4
- 69
- 4899
- 49
- 375
- 5041
- 6391
- 1
- 1071
- 169
- 1
- 551
- 2401
- 2116
- 10
- 361
- 5168
- 95
- 625
- 529
- 41
- 1900
- 576
- 876
- 208
- 1197
- 77
- 4096
- 9996
- 1681
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