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 22².
- 2.Use a² − b² = (a + b)(a − b) to find 32² − 9².
- 3.Use (a − b)² = a² − 2ab + b² to find 98².
- 4.Use (a − b)² = a² − 2ab + b² to find 31².
- 5.Find the value of x² − 2xy + y² when x = 7 and y = 4.
- 6.Use (a + b)(a − b) = a² − b² to find 63 × 57.
- 7.Use a² − b² = (a + b)(a − b) to find 70² − 29².
- 8.Use (a + b)² = a² + 2ab + b² to find 28².
- 9.Use (a + b)(a − b) = a² − b² to find 21 × 19.
- 10.If a + b = 12 and ab = 35, what is a² + b²?
- 11.Use (a + b)(a − b) = a² − b² to find 46 × 34.
- 12.Use (a + b)² = a² + 2ab + b² to find 38².
- 13.If a + b = 16 and ab = 63, what is a² + b²?
- 14.Use (a + b)² = a² + 2ab + b² to find 41².
- 15.If a + b = 4 and ab = 3, what is a² + b²?
- 16.Use (a − b)² = a² − 2ab + b² to find 57².
- 17.Use (a + b)(a − b) = a² − b² to find 72 × 68.
- 18.Use (a + b)² = a² + 2ab + b² to find 101².
- 19.If a − b = 1 and ab = 110, what is a² + b²?
- 20.Use (a − b)² = a² − 2ab + b² to find 99².
- 21.Use (a + b)(a − b) = a² − b² to find 82 × 78.
- 22.Use a² − b² = (a + b)(a − b) to find 76² − 2².
- 23.Use (a + b)² = a² + 2ab + b² to find 13².
- 24.Use (a − b)² = a² − 2ab + b² to find 64².
- 25.Use a² − b² = (a + b)(a − b) to find 45² − 12².
- 26.Use (a + b)² = a² + 2ab + b² to find 36².
- 27.Use a² − b² = (a + b)(a − b) to find 35² − 10².
- 28.Use (a + b)² = a² + 2ab + b² to find 12².
- 29.Use (a + b)(a − b) = a² − b² to find 77 × 63.
- 30.Use (a − b)² = a² − 2ab + b² to find 37².
- 31.If a − b = 3 and ab = 28, what is a² + b²?
- 32.Use a² − b² = (a + b)(a − b) to find 27² − 14².
- 33.Use (a − b)² = a² − 2ab + b² to find 35².
- 34.Find the value of x² + 2xy + y² when x = 4 and y = 3.
- 35.Use (a + b)(a − b) = a² − b² to find 74 × 66.
- 36.Use a² − b² = (a + b)(a − b) to find 40² − 14².
- 37.Use (a + b)(a − b) = a² − b² to find 22 × 18.
- 38.Use a² − b² = (a + b)(a − b) to find 74² − 6².
- 39.If a + b = 8 and ab = 12, what is a² + b²?
- 40.Use (a + b)(a − b) = a² − b² to find 93 × 87.
Answer key
- 484
- 943
- 9604
- 961
- 9
- 3591
- 4059
- 784
- 399
- 74
- 1564
- 1444
- 130
- 1681
- 10
- 3249
- 4896
- 10201
- 221
- 9801
- 6396
- 5772
- 169
- 4096
- 1881
- 1296
- 1125
- 144
- 4851
- 1369
- 65
- 533
- 1225
- 49
- 4884
- 1404
- 396
- 5440
- 40
- 8091
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets