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 66².
- 2.Use (a − b)² = a² − 2ab + b² to find 59².
- 3.Use (a − b)² = a² − 2ab + b² to find 83².
- 4.Use a² − b² = (a + b)(a − b) to find 80² − 53².
- 5.If a − b = 1 and ab = 72, what is a² + b²?
- 6.If a + b = 16 and ab = 48, what is a² + b²?
- 7.Use (a − b)² = a² − 2ab + b² to find 99².
- 8.Use (a + b)² = a² + 2ab + b² to find 69².
- 9.Use a² − b² = (a + b)(a − b) to find 59² − 3².
- 10.If a + b = 12 and ab = 11, what is a² + b²?
- 11.Use a² − b² = (a + b)(a − b) to find 21² − 6².
- 12.Use (a + b)² = a² + 2ab + b² to find 87².
- 13.Use (a + b)² = a² + 2ab + b² to find 42².
- 14.Use (a + b)² = a² + 2ab + b² to find 71².
- 15.Use (a + b)² = a² + 2ab + b² to find 66².
- 16.If a − b = 5 and ab = 66, what is a² + b²?
- 17.Use a² − b² = (a + b)(a − b) to find 43² − 12².
- 18.Use (a − b)² = a² − 2ab + b² to find 73².
- 19.Find the value of x² − 2xy + y² when x = 4 and y = 2.
- 20.Use a² − b² = (a + b)(a − b) to find 33² − 4².
- 21.Use a² − b² = (a + b)(a − b) to find 27² − 11².
- 22.Use (a + b)(a − b) = a² − b² to find 41 × 39.
- 23.If a + b = 9 and ab = 8, what is a² + b²?
- 24.Use (a − b)² = a² − 2ab + b² to find 16².
- 25.Use a² − b² = (a + b)(a − b) to find 60² − 48².
- 26.Use (a − b)² = a² − 2ab + b² to find 61².
- 27.Use (a − b)² = a² − 2ab + b² to find 75².
- 28.Use (a + b)² = a² + 2ab + b² to find 51².
- 29.If a + b = 22 and ab = 120, what is a² + b²?
- 30.Use (a − b)² = a² − 2ab + b² to find 53².
- 31.Use (a + b)² = a² + 2ab + b² to find 82².
- 32.Use (a − b)² = a² − 2ab + b² to find 91².
- 33.Use a² − b² = (a + b)(a − b) to find 59² − 38².
- 34.Find the value of x² − y² when x = 8 and y = 2.
- 35.Use (a + b)² = a² + 2ab + b² to find 37².
- 36.Use (a − b)² = a² − 2ab + b² to find 26².
- 37.Find the value of x² + 2xy + y² when x = 4 and y = 3.
- 38.Use a² − b² = (a + b)(a − b) to find 28² − 19².
- 39.If a − b = 2 and ab = 63, what is a² + b²?
- 40.Use (a + b)(a − b) = a² − b² to find 66 × 54.
Answer key
- 4356
- 3481
- 6889
- 3591
- 145
- 160
- 9801
- 4761
- 3472
- 122
- 405
- 7569
- 1764
- 5041
- 4356
- 157
- 1705
- 5329
- 4
- 1073
- 608
- 1599
- 65
- 256
- 1296
- 3721
- 5625
- 2601
- 244
- 2809
- 6724
- 8281
- 2037
- 60
- 1369
- 676
- 49
- 423
- 130
- 3564
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets