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)(a − b) = a² − b² to find 34 × 26.
- 2.Use (a + b)(a − b) = a² − b² to find 103 × 97.
- 3.Use a² − b² = (a + b)(a − b) to find 48² − 2².
- 4.Use (a − b)² = a² − 2ab + b² to find 34².
- 5.Use (a − b)² = a² − 2ab + b² to find 47².
- 6.Use (a − b)² = a² − 2ab + b² to find 29².
- 7.Use (a − b)² = a² − 2ab + b² to find 59².
- 8.Find the value of x² + 2xy + y² when x = 10 and y = 1.
- 9.Use (a + b)(a − b) = a² − b² to find 86 × 74.
- 10.Use a² − b² = (a + b)(a − b) to find 73² − 46².
- 11.Find the value of x² − y² when x = 14 and y = 10.
- 12.Use (a + b)² = a² + 2ab + b² to find 101².
- 13.If a − b = 4 and ab = 21, what is a² + b²?
- 14.Find the value of x² − 2xy + y² when x = 3 and y = 2.
- 15.Use (a + b)(a − b) = a² − b² to find 49 × 31.
- 16.Find the value of x² − y² when x = 14 and y = 2.
- 17.If a + b = 3 and ab = 2, what is a² + b²?
- 18.If a − b = 1 and ab = 90, what is a² + b²?
- 19.Use (a + b)² = a² + 2ab + b² to find 93².
- 20.Use (a + b)² = a² + 2ab + b² to find 72².
- 21.Use (a + b)² = a² + 2ab + b² to find 51².
- 22.Use (a + b)² = a² + 2ab + b² to find 47².
- 23.If a + b = 21 and ab = 110, what is a² + b²?
- 24.Use a² − b² = (a + b)(a − b) to find 55² − 25².
- 25.Use (a + b)(a − b) = a² − b² to find 31 × 29.
- 26.Find the value of x² + 2xy + y² when x = 7 and y = 3.
- 27.If a − b = 9 and ab = 10, what is a² + b²?
- 28.Use (a + b)(a − b) = a² − b² to find 35 × 25.
- 29.Use (a − b)² = a² − 2ab + b² to find 69².
- 30.Use (a + b)(a − b) = a² − b² to find 104 × 96.
- 31.If a + b = 9 and ab = 8, what is a² + b²?
- 32.If a + b = 18 and ab = 80, what is a² + b²?
- 33.Use (a + b)(a − b) = a² − b² to find 22 × 18.
- 34.Use a² − b² = (a + b)(a − b) to find 64² − 19².
- 35.Use (a + b)(a − b) = a² − b² to find 36 × 24.
- 36.Use (a − b)² = a² − 2ab + b² to find 79².
- 37.Use (a − b)² = a² − 2ab + b² to find 77².
- 38.If a − b = 2 and ab = 24, what is a² + b²?
- 39.Use (a + b)(a − b) = a² − b² to find 59 × 41.
- 40.Use a² − b² = (a + b)(a − b) to find 72² − 59².
Answer key
- 884
- 9991
- 2300
- 1156
- 2209
- 841
- 3481
- 121
- 6364
- 3213
- 96
- 10201
- 58
- 1
- 1519
- 192
- 5
- 181
- 8649
- 5184
- 2601
- 2209
- 221
- 2400
- 899
- 100
- 101
- 875
- 4761
- 9984
- 65
- 164
- 396
- 3735
- 864
- 6241
- 5929
- 52
- 2419
- 1703
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