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 96² − 33².
- 2.Find the value of x² − y² when x = 12 and y = 9.
- 3.Use (a + b)² = a² + 2ab + b² to find 13².
- 4.Use (a + b)² = a² + 2ab + b² to find 27².
- 5.Find the value of x² − 2xy + y² when x = 12 and y = 5.
- 6.If a − b = 3 and ab = 4, what is a² + b²?
- 7.Find the value of x² + 2xy + y² when x = 7 and y = 4.
- 8.Use a² − b² = (a + b)(a − b) to find 55² − 53².
- 9.Use (a + b)² = a² + 2ab + b² to find 74².
- 10.Find the value of x² − y² when x = 6 and y = 1.
- 11.Use (a + b)(a − b) = a² − b² to find 48 × 32.
- 12.Use (a + b)² = a² + 2ab + b² to find 32².
- 13.Use (a − b)² = a² − 2ab + b² to find 91².
- 14.If a − b = 5 and ab = 66, what is a² + b²?
- 15.Use a² − b² = (a + b)(a − b) to find 41² − 36².
- 16.Use a² − b² = (a + b)(a − b) to find 25² − 1².
- 17.Use (a − b)² = a² − 2ab + b² to find 99².
- 18.If a + b = 11 and ab = 30, what is a² + b²?
- 19.Use (a + b)(a − b) = a² − b² to find 91 × 89.
- 20.If a + b = 17 and ab = 70, what is a² + b²?
- 21.Use a² − b² = (a + b)(a − b) to find 63² − 38².
- 22.Use (a − b)² = a² − 2ab + b² to find 57².
- 23.Use a² − b² = (a + b)(a − b) to find 52² − 5².
- 24.Use (a + b)(a − b) = a² − b² to find 95 × 85.
- 25.Use (a + b)(a − b) = a² − b² to find 21 × 19.
- 26.Use (a + b)² = a² + 2ab + b² to find 81².
- 27.Use (a − b)² = a² − 2ab + b² to find 69².
- 28.Use (a − b)² = a² − 2ab + b² to find 74².
- 29.Use (a + b)(a − b) = a² − b² to find 52 × 48.
- 30.Find the value of x² − 2xy + y² when x = 13 and y = 9.
- 31.If a + b = 14 and ab = 48, what is a² + b²?
- 32.Use a² − b² = (a + b)(a − b) to find 72² − 70².
- 33.If a + b = 6 and ab = 8, what is a² + b²?
- 34.If a − b = 6 and ab = 72, what is a² + b²?
- 35.Use (a + b)² = a² + 2ab + b² to find 59².
- 36.Use a² − b² = (a + b)(a − b) to find 30² − 7².
- 37.If a − b = 1 and ab = 2, what is a² + b²?
- 38.Use (a − b)² = a² − 2ab + b² to find 95².
- 39.Find the value of x² − y² when x = 12 and y = 2.
- 40.Use (a + b)(a − b) = a² − b² to find 26 × 14.
Answer key
- 8127
- 63
- 169
- 729
- 49
- 17
- 121
- 216
- 5476
- 35
- 1536
- 1024
- 8281
- 157
- 385
- 624
- 9801
- 61
- 8099
- 149
- 2525
- 3249
- 2679
- 8075
- 399
- 6561
- 4761
- 5476
- 2496
- 16
- 100
- 284
- 20
- 180
- 3481
- 851
- 5
- 9025
- 140
- 364
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