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 a² − b² = (a + b)(a − b) to find 95² − 2².
- 2.Use (a − b)² = a² − 2ab + b² to find 63².
- 3.Use a² − b² = (a + b)(a − b) to find 87² − 41².
- 4.Use a² − b² = (a + b)(a − b) to find 43² − 28².
- 5.Use (a − b)² = a² − 2ab + b² to find 93².
- 6.Use a² − b² = (a + b)(a − b) to find 86² − 54².
- 7.Use (a + b)² = a² + 2ab + b² to find 82².
- 8.Find the value of x² − 2xy + y² when x = 4 and y = 1.
- 9.Use (a + b)(a − b) = a² − b² to find 59 × 41.
- 10.Use a² − b² = (a + b)(a − b) to find 47² − 29².
- 11.Use (a − b)² = a² − 2ab + b² to find 66².
- 12.Use a² − b² = (a + b)(a − b) to find 59² − 44².
- 13.Use (a + b)² = a² + 2ab + b² to find 76².
- 14.Use (a − b)² = a² − 2ab + b² to find 46².
- 15.Find the value of x² − y² when x = 10 and y = 9.
- 16.Use (a + b)² = a² + 2ab + b² to find 22².
- 17.Use (a − b)² = a² − 2ab + b² to find 69².
- 18.If a − b = 8 and ab = 9, what is a² + b²?
- 19.Use a² − b² = (a + b)(a − b) to find 79² − 2².
- 20.Find the value of x² − 2xy + y² when x = 5 and y = 4.
- 21.If a + b = 10 and ab = 9, what is a² + b²?
- 22.Find the value of x² − 2xy + y² when x = 9 and y = 3.
- 23.Find the value of x² − y² when x = 5 and y = 3.
- 24.Find the value of x² − 2xy + y² when x = 12 and y = 10.
- 25.Use (a − b)² = a² − 2ab + b² to find 25².
- 26.Use (a + b)² = a² + 2ab + b² to find 95².
- 27.If a + b = 23 and ab = 132, what is a² + b²?
- 28.Use (a − b)² = a² − 2ab + b² to find 41².
- 29.Use a² − b² = (a + b)(a − b) to find 51² − 5².
- 30.Find the value of x² + 2xy + y² when x = 3 and y = 2.
- 31.Use (a − b)² = a² − 2ab + b² to find 37².
- 32.Use (a + b)² = a² + 2ab + b² to find 62².
- 33.Find the value of x² − y² when x = 11 and y = 2.
- 34.Use (a − b)² = a² − 2ab + b² to find 19².
- 35.Find the value of x² + 2xy + y² when x = 6 and y = 2.
- 36.Use (a − b)² = a² − 2ab + b² to find 34².
- 37.Use (a + b)² = a² + 2ab + b² to find 72².
- 38.Use (a − b)² = a² − 2ab + b² to find 83².
- 39.Use (a + b)(a − b) = a² − b² to find 75 × 65.
- 40.Use (a + b)(a − b) = a² − b² to find 89 × 71.
Answer key
- 9021
- 3969
- 5888
- 1065
- 8649
- 4480
- 6724
- 9
- 2419
- 1368
- 4356
- 1545
- 5776
- 2116
- 19
- 484
- 4761
- 82
- 6237
- 1
- 82
- 36
- 16
- 4
- 625
- 9025
- 265
- 1681
- 2576
- 25
- 1369
- 3844
- 117
- 361
- 64
- 1156
- 5184
- 6889
- 4875
- 6319
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