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.Find the value of x² − y² when x = 8 and y = 6.
- 2.If a + b = 4 and ab = 3, what is a² + b²?
- 3.Use a² − b² = (a + b)(a − b) to find 81² − 71².
- 4.Use (a + b)(a − b) = a² − b² to find 67 × 53.
- 5.Use a² − b² = (a + b)(a − b) to find 76² − 28².
- 6.Use (a − b)² = a² − 2ab + b² to find 41².
- 7.Use (a − b)² = a² − 2ab + b² to find 69².
- 8.Use a² − b² = (a + b)(a − b) to find 37² − 1².
- 9.Find the value of x² − y² when x = 4 and y = 3.
- 10.Use (a − b)² = a² − 2ab + b² to find 55².
- 11.Find the value of x² − y² when x = 14 and y = 3.
- 12.Use (a − b)² = a² − 2ab + b² to find 97².
- 13.Use (a + b)² = a² + 2ab + b² to find 42².
- 14.Find the value of x² − y² when x = 12 and y = 1.
- 15.Find the value of x² − 2xy + y² when x = 4 and y = 2.
- 16.Use a² − b² = (a + b)(a − b) to find 62² − 61².
- 17.Use (a + b)² = a² + 2ab + b² to find 89².
- 18.Find the value of x² − 2xy + y² when x = 4 and y = 3.
- 19.Use (a − b)² = a² − 2ab + b² to find 16².
- 20.Use (a − b)² = a² − 2ab + b² to find 19².
- 21.Use (a + b)(a − b) = a² − b² to find 51 × 49.
- 22.Use (a + b)(a − b) = a² − b² to find 35 × 25.
- 23.Use (a − b)² = a² − 2ab + b² to find 26².
- 24.Use (a + b)(a − b) = a² − b² to find 104 × 96.
- 25.Use a² − b² = (a + b)(a − b) to find 73² − 51².
- 26.If a − b = 8 and ab = 33, what is a² + b²?
- 27.Use (a + b)² = a² + 2ab + b² to find 64².
- 28.Use (a + b)² = a² + 2ab + b² to find 36².
- 29.Use a² − b² = (a + b)(a − b) to find 82² − 50².
- 30.Use (a + b)² = a² + 2ab + b² to find 37².
- 31.Use (a + b)(a − b) = a² − b² to find 103 × 97.
- 32.Find the value of x² − y² when x = 10 and y = 3.
- 33.Use (a + b)² = a² + 2ab + b² to find 86².
- 34.Find the value of x² + 2xy + y² when x = 12 and y = 5.
- 35.Use a² − b² = (a + b)(a − b) to find 74² − 71².
- 36.Use a² − b² = (a + b)(a − b) to find 20² − 15².
- 37.Use (a − b)² = a² − 2ab + b² to find 45².
- 38.Use (a + b)² = a² + 2ab + b² to find 97².
- 39.If a − b = 6 and ab = 16, what is a² + b²?
- 40.Use (a + b)(a − b) = a² − b² to find 42 × 38.
Answer key
- 28
- 10
- 1520
- 3551
- 4992
- 1681
- 4761
- 1368
- 7
- 3025
- 187
- 9409
- 1764
- 143
- 4
- 123
- 7921
- 1
- 256
- 361
- 2499
- 875
- 676
- 9984
- 2728
- 130
- 4096
- 1296
- 4224
- 1369
- 9991
- 91
- 7396
- 289
- 435
- 175
- 2025
- 9409
- 68
- 1596
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets