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)² = a² + 2ab + b² to find 97².
- 2.Use (a + b)(a − b) = a² − b² to find 42 × 38.
- 3.Use (a + b)(a − b) = a² − b² to find 48 × 32.
- 4.Use (a + b)² = a² + 2ab + b² to find 71².
- 5.Find the value of x² − y² when x = 9 and y = 3.
- 6.Use (a + b)(a − b) = a² − b² to find 71 × 69.
- 7.If a − b = 2 and ab = 24, what is a² + b²?
- 8.Use a² − b² = (a + b)(a − b) to find 22² − 17².
- 9.If a − b = 1 and ab = 2, what is a² + b²?
- 10.If a − b = 1 and ab = 12, what is a² + b²?
- 11.Find the value of x² − y² when x = 11 and y = 9.
- 12.If a − b = 4 and ab = 12, what is a² + b²?
- 13.Use a² − b² = (a + b)(a − b) to find 28² − 25².
- 14.If a − b = 2 and ab = 3, what is a² + b²?
- 15.Use (a − b)² = a² − 2ab + b² to find 25².
- 16.Use (a − b)² = a² − 2ab + b² to find 36².
- 17.Use a² − b² = (a + b)(a − b) to find 31² − 25².
- 18.Use (a − b)² = a² − 2ab + b² to find 46².
- 19.Find the value of x² + 2xy + y² when x = 15 and y = 1.
- 20.Use (a + b)(a − b) = a² − b² to find 64 × 56.
- 21.If a − b = 10 and ab = 24, what is a² + b²?
- 22.Use (a − b)² = a² − 2ab + b² to find 63².
- 23.Use a² − b² = (a + b)(a − b) to find 47² − 12².
- 24.If a − b = 6 and ab = 16, what is a² + b²?
- 25.If a − b = 9 and ab = 10, what is a² + b²?
- 26.Use (a + b)² = a² + 2ab + b² to find 96².
- 27.Use (a − b)² = a² − 2ab + b² to find 24².
- 28.Use (a + b)(a − b) = a² − b² to find 35 × 25.
- 29.Use (a − b)² = a² − 2ab + b² to find 19².
- 30.Use (a + b)² = a² + 2ab + b² to find 91².
- 31.Use (a − b)² = a² − 2ab + b² to find 66².
- 32.Use (a − b)² = a² − 2ab + b² to find 52².
- 33.Use a² − b² = (a + b)(a − b) to find 40² − 36².
- 34.Use (a + b)² = a² + 2ab + b² to find 64².
- 35.Find the value of x² − y² when x = 12 and y = 8.
- 36.Use a² − b² = (a + b)(a − b) to find 60² − 4².
- 37.Use a² − b² = (a + b)(a − b) to find 76² − 46².
- 38.Use (a + b)² = a² + 2ab + b² to find 86².
- 39.Use (a + b)² = a² + 2ab + b² to find 45².
- 40.Use (a + b)² = a² + 2ab + b² to find 63².
Answer key
- 9409
- 1596
- 1536
- 5041
- 72
- 4899
- 52
- 195
- 5
- 25
- 40
- 40
- 159
- 10
- 625
- 1296
- 336
- 2116
- 256
- 3584
- 148
- 3969
- 2065
- 68
- 101
- 9216
- 576
- 875
- 361
- 8281
- 4356
- 2704
- 304
- 4096
- 80
- 3584
- 3660
- 7396
- 2025
- 3969
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets