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 60² − 11².
- 2.Use (a + b)² = a² + 2ab + b² to find 73².
- 3.Use (a + b)² = a² + 2ab + b² to find 76².
- 4.Use (a + b)(a − b) = a² − b² to find 66 × 54.
- 5.Use (a + b)² = a² + 2ab + b² to find 62².
- 6.Use (a − b)² = a² − 2ab + b² to find 38².
- 7.Use (a − b)² = a² − 2ab + b² to find 28².
- 8.If a + b = 11 and ab = 24, what is a² + b²?
- 9.Use (a − b)² = a² − 2ab + b² to find 43².
- 10.Use (a + b)(a − b) = a² − b² to find 36 × 24.
- 11.Use (a + b)(a − b) = a² − b² to find 89 × 71.
- 12.Use (a − b)² = a² − 2ab + b² to find 44².
- 13.If a + b = 14 and ab = 48, what is a² + b²?
- 14.Use (a + b)(a − b) = a² − b² to find 105 × 95.
- 15.Use (a + b)(a − b) = a² − b² to find 22 × 18.
- 16.Use (a + b)² = a² + 2ab + b² to find 105².
- 17.Use (a − b)² = a² − 2ab + b² to find 88².
- 18.If a + b = 10 and ab = 21, what is a² + b²?
- 19.Use (a − b)² = a² − 2ab + b² to find 17².
- 20.Find the value of x² − 2xy + y² when x = 6 and y = 1.
- 21.Use (a + b)² = a² + 2ab + b² to find 106².
- 22.Find the value of x² − 2xy + y² when x = 9 and y = 3.
- 23.Use (a + b)(a − b) = a² − b² to find 52 × 48.
- 24.If a + b = 5 and ab = 4, what is a² + b²?
- 25.Use (a + b)² = a² + 2ab + b² to find 77².
- 26.Use (a + b)(a − b) = a² − b² to find 44 × 36.
- 27.Use (a − b)² = a² − 2ab + b² to find 48².
- 28.If a − b = 2 and ab = 24, what is a² + b²?
- 29.Use a² − b² = (a + b)(a − b) to find 93² − 70².
- 30.Use (a + b)² = a² + 2ab + b² to find 99².
- 31.Use (a − b)² = a² − 2ab + b² to find 72².
- 32.Use a² − b² = (a + b)(a − b) to find 58² − 12².
- 33.Use (a + b)² = a² + 2ab + b² to find 12².
- 34.Use (a + b)² = a² + 2ab + b² to find 36².
- 35.Use (a + b)(a − b) = a² − b² to find 83 × 77.
- 36.Find the value of x² − y² when x = 3 and y = 1.
- 37.Find the value of x² − 2xy + y² when x = 11 and y = 1.
- 38.Use a² − b² = (a + b)(a − b) to find 98² − 34².
- 39.Use (a + b)(a − b) = a² − b² to find 64 × 56.
- 40.Find the value of x² − y² when x = 14 and y = 6.
Answer key
- 3479
- 5329
- 5776
- 3564
- 3844
- 1444
- 784
- 73
- 1849
- 864
- 6319
- 1936
- 100
- 9975
- 396
- 11025
- 7744
- 58
- 289
- 25
- 11236
- 36
- 2496
- 17
- 5929
- 1584
- 2304
- 52
- 3749
- 9801
- 5184
- 3220
- 144
- 1296
- 6391
- 8
- 100
- 8448
- 3584
- 160
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