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 a² − b² = (a + b)(a − b) to find 69² − 24².
- 2.If a − b = 2 and ab = 35, what is a² + b²?
- 3.Use (a − b)² = a² − 2ab + b² to find 24².
- 4.Use (a + b)(a − b) = a² − b² to find 56 × 44.
- 5.Find the value of x² − y² when x = 3 and y = 1.
- 6.Find the value of x² − 2xy + y² when x = 13 and y = 2.
- 7.Use (a + b)(a − b) = a² − b² to find 58 × 42.
- 8.Find the value of x² + 2xy + y² when x = 5 and y = 2.
- 9.Use (a − b)² = a² − 2ab + b² to find 94².
- 10.Use (a + b)² = a² + 2ab + b² to find 17².
- 11.Find the value of x² − y² when x = 14 and y = 5.
- 12.Find the value of x² + 2xy + y² when x = 14 and y = 13.
- 13.Find the value of x² + 2xy + y² when x = 5 and y = 4.
- 14.Use (a + b)(a − b) = a² − b² to find 43 × 37.
- 15.Find the value of x² + 2xy + y² when x = 12 and y = 11.
- 16.Use a² − b² = (a + b)(a − b) to find 35² − 1².
- 17.Use (a + b)² = a² + 2ab + b² to find 79².
- 18.Find the value of x² + 2xy + y² when x = 14 and y = 11.
- 19.Find the value of x² − y² when x = 9 and y = 4.
- 20.If a − b = 7 and ab = 8, what is a² + b²?
- 21.Find the value of x² + 2xy + y² when x = 3 and y = 1.
- 22.Use (a − b)² = a² − 2ab + b² to find 79².
- 23.If a + b = 7 and ab = 6, what is a² + b²?
- 24.Use a² − b² = (a + b)(a − b) to find 53² − 11².
- 25.If a − b = 7 and ab = 18, what is a² + b²?
- 26.Use a² − b² = (a + b)(a − b) to find 37² − 15².
- 27.Use (a − b)² = a² − 2ab + b² to find 33².
- 28.Find the value of x² − 2xy + y² when x = 6 and y = 1.
- 29.Use a² − b² = (a + b)(a − b) to find 56² − 16².
- 30.Use (a + b)² = a² + 2ab + b² to find 85².
- 31.Use a² − b² = (a + b)(a − b) to find 99² − 50².
- 32.Use (a − b)² = a² − 2ab + b² to find 23².
- 33.Use (a + b)² = a² + 2ab + b² to find 97².
- 34.If a + b = 9 and ab = 20, what is a² + b²?
- 35.Use a² − b² = (a + b)(a − b) to find 67² − 23².
- 36.Use (a + b)(a − b) = a² − b² to find 76 × 64.
- 37.Use (a + b)(a − b) = a² − b² to find 38 × 22.
- 38.Use (a + b)² = a² + 2ab + b² to find 102².
- 39.Use (a + b)(a − b) = a² − b² to find 73 × 67.
- 40.Find the value of x² + 2xy + y² when x = 4 and y = 3.
Answer key
- 4185
- 74
- 576
- 2464
- 8
- 121
- 2436
- 49
- 8836
- 289
- 171
- 729
- 81
- 1591
- 529
- 1224
- 6241
- 625
- 65
- 65
- 16
- 6241
- 37
- 2688
- 85
- 1144
- 1089
- 25
- 2880
- 7225
- 7301
- 529
- 9409
- 41
- 3960
- 4864
- 836
- 10404
- 4891
- 49
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