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 (a + b)(a − b) = a² − b² to find 43 × 37.
- 2.Use (a + b)(a − b) = a² − b² to find 65 × 55.
- 3.If a − b = 7 and ab = 18, what is a² + b²?
- 4.Use (a + b)(a − b) = a² − b² to find 93 × 87.
- 5.Use (a + b)(a − b) = a² − b² to find 79 × 61.
- 6.Use (a − b)² = a² − 2ab + b² to find 26².
- 7.Use a² − b² = (a + b)(a − b) to find 36² − 8².
- 8.If a + b = 19 and ab = 88, what is a² + b²?
- 9.Find the value of x² + 2xy + y² when x = 4 and y = 1.
- 10.Use (a − b)² = a² − 2ab + b² to find 98².
- 11.Use (a + b)(a − b) = a² − b² to find 35 × 25.
- 12.Find the value of x² − y² when x = 7 and y = 6.
- 13.Use (a + b)² = a² + 2ab + b² to find 96².
- 14.Use (a + b)² = a² + 2ab + b² to find 27².
- 15.Use (a + b)² = a² + 2ab + b² to find 16².
- 16.Use (a − b)² = a² − 2ab + b² to find 14².
- 17.Find the value of x² − 2xy + y² when x = 7 and y = 4.
- 18.Use (a − b)² = a² − 2ab + b² to find 15².
- 19.If a − b = 6 and ab = 16, what is a² + b²?
- 20.Use a² − b² = (a + b)(a − b) to find 24² − 23².
- 21.Use (a + b)(a − b) = a² − b² to find 26 × 14.
- 22.Use (a − b)² = a² − 2ab + b² to find 59².
- 23.Find the value of x² − 2xy + y² when x = 9 and y = 6.
- 24.Find the value of x² + 2xy + y² when x = 13 and y = 12.
- 25.Find the value of x² + 2xy + y² when x = 14 and y = 12.
- 26.Use a² − b² = (a + b)(a − b) to find 57² − 49².
- 27.Find the value of x² − 2xy + y² when x = 15 and y = 1.
- 28.If a − b = 2 and ab = 8, what is a² + b²?
- 29.Use a² − b² = (a + b)(a − b) to find 24² − 12².
- 30.Find the value of x² + 2xy + y² when x = 6 and y = 3.
- 31.Use (a + b)² = a² + 2ab + b² to find 98².
- 32.If a − b = 9 and ab = 36, what is a² + b²?
- 33.Use (a + b)(a − b) = a² − b² to find 32 × 28.
- 34.If a + b = 3 and ab = 2, what is a² + b²?
- 35.If a + b = 20 and ab = 96, what is a² + b²?
- 36.Use (a + b)(a − b) = a² − b² to find 41 × 39.
- 37.Use (a − b)² = a² − 2ab + b² to find 93².
- 38.Find the value of x² + 2xy + y² when x = 5 and y = 1.
- 39.Find the value of x² + 2xy + y² when x = 9 and y = 6.
- 40.Use a² − b² = (a + b)(a − b) to find 73² − 61².
Answer key
- 1591
- 3575
- 85
- 8091
- 4819
- 676
- 1232
- 185
- 25
- 9604
- 875
- 13
- 9216
- 729
- 256
- 196
- 9
- 225
- 68
- 47
- 364
- 3481
- 9
- 625
- 676
- 848
- 196
- 20
- 432
- 81
- 9604
- 153
- 896
- 5
- 208
- 1599
- 8649
- 36
- 225
- 1608
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