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 − 2xy + y² when x = 6 and y = 2.
- 2.Use (a − b)² = a² − 2ab + b² to find 77².
- 3.Use (a + b)² = a² + 2ab + b² to find 18².
- 4.Use a² − b² = (a + b)(a − b) to find 99² − 1².
- 5.Use (a + b)(a − b) = a² − b² to find 51 × 49.
- 6.Use (a + b)(a − b) = a² − b² to find 87 × 73.
- 7.Use (a − b)² = a² − 2ab + b² to find 37².
- 8.Use (a − b)² = a² − 2ab + b² to find 39².
- 9.Use (a + b)² = a² + 2ab + b² to find 24².
- 10.If a + b = 3 and ab = 2, what is a² + b²?
- 11.If a + b = 5 and ab = 4, what is a² + b²?
- 12.Use (a + b)² = a² + 2ab + b² to find 17².
- 13.Use a² − b² = (a + b)(a − b) to find 42² − 20².
- 14.Find the value of x² − y² when x = 5 and y = 2.
- 15.Use (a + b)(a − b) = a² − b² to find 65 × 55.
- 16.Use (a + b)² = a² + 2ab + b² to find 72².
- 17.Use a² − b² = (a + b)(a − b) to find 42² − 12².
- 18.Use (a − b)² = a² − 2ab + b² to find 54².
- 19.Find the value of x² + 2xy + y² when x = 13 and y = 7.
- 20.Find the value of x² − 2xy + y² when x = 15 and y = 7.
- 21.Use (a − b)² = a² − 2ab + b² to find 88².
- 22.Use a² − b² = (a + b)(a − b) to find 43² − 31².
- 23.Use (a + b)² = a² + 2ab + b² to find 26².
- 24.Use a² − b² = (a + b)(a − b) to find 29² − 16².
- 25.Use (a − b)² = a² − 2ab + b² to find 31².
- 26.Use (a + b)² = a² + 2ab + b² to find 105².
- 27.Use (a + b)² = a² + 2ab + b² to find 48².
- 28.Use (a − b)² = a² − 2ab + b² to find 55².
- 29.If a + b = 5 and ab = 6, what is a² + b²?
- 30.Use a² − b² = (a + b)(a − b) to find 62² − 51².
- 31.Use (a + b)² = a² + 2ab + b² to find 11².
- 32.If a + b = 9 and ab = 14, what is a² + b²?
- 33.Use (a − b)² = a² − 2ab + b² to find 69².
- 34.Use (a − b)² = a² − 2ab + b² to find 19².
- 35.Use (a − b)² = a² − 2ab + b² to find 35².
- 36.Find the value of x² − 2xy + y² when x = 15 and y = 12.
- 37.Use (a − b)² = a² − 2ab + b² to find 84².
- 38.Use (a + b)(a − b) = a² − b² to find 59 × 41.
- 39.Use (a + b)² = a² + 2ab + b² to find 69².
- 40.Use (a − b)² = a² − 2ab + b² to find 46².
Answer key
- 16
- 5929
- 324
- 9800
- 2499
- 6351
- 1369
- 1521
- 576
- 5
- 17
- 289
- 1364
- 21
- 3575
- 5184
- 1620
- 2916
- 400
- 64
- 7744
- 888
- 676
- 585
- 961
- 11025
- 2304
- 3025
- 13
- 1243
- 121
- 53
- 4761
- 361
- 1225
- 9
- 7056
- 2419
- 4761
- 2116
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets