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)² = a² − 2ab + b² to find 57².
- 2.Use (a + b)(a − b) = a² − b² to find 95 × 85.
- 3.Use (a + b)² = a² + 2ab + b² to find 48².
- 4.Use (a + b)(a − b) = a² − b² to find 107 × 93.
- 5.Use (a + b)(a − b) = a² − b² to find 62 × 58.
- 6.Use a² − b² = (a + b)(a − b) to find 81² − 49².
- 7.Use (a + b)² = a² + 2ab + b² to find 101².
- 8.Find the value of x² + 2xy + y² when x = 5 and y = 1.
- 9.If a − b = 9 and ab = 36, what is a² + b²?
- 10.Use (a + b)(a − b) = a² − b² to find 51 × 49.
- 11.Use (a − b)² = a² − 2ab + b² to find 98².
- 12.Find the value of x² − 2xy + y² when x = 5 and y = 4.
- 13.If a − b = 1 and ab = 20, what is a² + b²?
- 14.Use (a − b)² = a² − 2ab + b² to find 76².
- 15.If a + b = 10 and ab = 16, what is a² + b²?
- 16.If a − b = 7 and ab = 8, what is a² + b²?
- 17.Use (a + b)(a − b) = a² − b² to find 49 × 31.
- 18.If a − b = 1 and ab = 12, what is a² + b²?
- 19.Find the value of x² − y² when x = 8 and y = 1.
- 20.Use (a − b)² = a² − 2ab + b² to find 71².
- 21.Find the value of x² − y² when x = 7 and y = 1.
- 22.Use (a + b)² = a² + 2ab + b² to find 83².
- 23.If a + b = 10 and ab = 9, what is a² + b²?
- 24.Use (a + b)(a − b) = a² − b² to find 81 × 79.
- 25.Use a² − b² = (a + b)(a − b) to find 81² − 71².
- 26.If a + b = 4 and ab = 3, what is a² + b²?
- 27.If a + b = 11 and ab = 24, what is a² + b²?
- 28.Find the value of x² − 2xy + y² when x = 5 and y = 2.
- 29.Use (a + b)² = a² + 2ab + b² to find 27².
- 30.Use (a + b)² = a² + 2ab + b² to find 22².
- 31.Use a² − b² = (a + b)(a − b) to find 44² − 6².
- 32.Use a² − b² = (a + b)(a − b) to find 37² − 33².
- 33.Use (a − b)² = a² − 2ab + b² to find 61².
- 34.If a + b = 9 and ab = 14, what is a² + b²?
- 35.If a + b = 16 and ab = 48, what is a² + b²?
- 36.Use a² − b² = (a + b)(a − b) to find 69² − 66².
- 37.Use (a + b)(a − b) = a² − b² to find 93 × 87.
- 38.Use (a + b)² = a² + 2ab + b² to find 13².
- 39.Use (a + b)² = a² + 2ab + b² to find 92².
- 40.Use a² − b² = (a + b)(a − b) to find 25² − 8².
Answer key
- 3249
- 8075
- 2304
- 9951
- 3596
- 4160
- 10201
- 36
- 153
- 2499
- 9604
- 1
- 41
- 5776
- 68
- 65
- 1519
- 25
- 63
- 5041
- 48
- 6889
- 82
- 6399
- 1520
- 10
- 73
- 9
- 729
- 484
- 1900
- 280
- 3721
- 53
- 160
- 405
- 8091
- 169
- 8464
- 561
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