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 = 8 and y = 2.
- 2.If a − b = 3 and ab = 10, what is a² + b²?
- 3.If a + b = 9 and ab = 14, what is a² + b²?
- 4.Use (a + b)(a − b) = a² − b² to find 31 × 29.
- 5.Use (a + b)(a − b) = a² − b² to find 101 × 99.
- 6.If a + b = 10 and ab = 9, what is a² + b²?
- 7.Use (a − b)² = a² − 2ab + b² to find 94².
- 8.Use (a + b)² = a² + 2ab + b² to find 71².
- 9.Use (a + b)(a − b) = a² − b² to find 67 × 53.
- 10.Use (a − b)² = a² − 2ab + b² to find 71².
- 11.If a − b = 2 and ab = 3, what is a² + b²?
- 12.Use a² − b² = (a + b)(a − b) to find 61² − 35².
- 13.Use (a + b)² = a² + 2ab + b² to find 41².
- 14.Use (a + b)² = a² + 2ab + b² to find 99².
- 15.Use (a − b)² = a² − 2ab + b² to find 68².
- 16.Use (a + b)² = a² + 2ab + b² to find 37².
- 17.Find the value of x² + 2xy + y² when x = 12 and y = 11.
- 18.If a − b = 3 and ab = 88, what is a² + b²?
- 19.Find the value of x² − 2xy + y² when x = 15 and y = 10.
- 20.Use a² − b² = (a + b)(a − b) to find 88² − 18².
- 21.Use a² − b² = (a + b)(a − b) to find 59² − 14².
- 22.Use a² − b² = (a + b)(a − b) to find 87² − 12².
- 23.Use (a + b)(a − b) = a² − b² to find 64 × 56.
- 24.Use a² − b² = (a + b)(a − b) to find 90² − 48².
- 25.Use (a − b)² = a² − 2ab + b² to find 49².
- 26.If a + b = 12 and ab = 20, what is a² + b²?
- 27.Use (a + b)² = a² + 2ab + b² to find 13².
- 28.Find the value of x² − y² when x = 11 and y = 10.
- 29.Use (a + b)² = a² + 2ab + b² to find 86².
- 30.If a + b = 13 and ab = 12, what is a² + b²?
- 31.Use (a − b)² = a² − 2ab + b² to find 26².
- 32.Use a² − b² = (a + b)(a − b) to find 31² − 25².
- 33.Use a² − b² = (a + b)(a − b) to find 91² − 8².
- 34.Find the value of x² + 2xy + y² when x = 12 and y = 4.
- 35.Use (a − b)² = a² − 2ab + b² to find 43².
- 36.Use (a + b)(a − b) = a² − b² to find 61 × 59.
- 37.Use a² − b² = (a + b)(a − b) to find 27² − 18².
- 38.Use (a + b)(a − b) = a² − b² to find 93 × 87.
- 39.Use (a − b)² = a² − 2ab + b² to find 95².
- 40.Use (a + b)(a − b) = a² − b² to find 104 × 96.
Answer key
- 100
- 29
- 53
- 899
- 9999
- 82
- 8836
- 5041
- 3551
- 5041
- 10
- 2496
- 1681
- 9801
- 4624
- 1369
- 529
- 185
- 25
- 7420
- 3285
- 7425
- 3584
- 5796
- 2401
- 104
- 169
- 21
- 7396
- 145
- 676
- 336
- 8217
- 256
- 1849
- 3599
- 405
- 8091
- 9025
- 9984
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets