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 = 11 and y = 2.
- 2.If a + b = 16 and ab = 55, what is a² + b²?
- 3.Use (a + b)(a − b) = a² − b² to find 32 × 28.
- 4.Use (a + b)(a − b) = a² − b² to find 44 × 36.
- 5.Use (a − b)² = a² − 2ab + b² to find 11².
- 6.If a − b = 10 and ab = 24, what is a² + b²?
- 7.If a + b = 14 and ab = 48, what is a² + b²?
- 8.If a − b = 6 and ab = 7, what is a² + b²?
- 9.Use (a + b)(a − b) = a² − b² to find 38 × 22.
- 10.Use (a + b)² = a² + 2ab + b² to find 103².
- 11.Use (a + b)² = a² + 2ab + b² to find 41².
- 12.Use (a + b)(a − b) = a² − b² to find 81 × 79.
- 13.If a + b = 7 and ab = 12, what is a² + b²?
- 14.If a − b = 1 and ab = 2, what is a² + b²?
- 15.Use (a − b)² = a² − 2ab + b² to find 68².
- 16.Use (a − b)² = a² − 2ab + b² to find 39².
- 17.Use (a − b)² = a² − 2ab + b² to find 49².
- 18.Find the value of x² + 2xy + y² when x = 4 and y = 1.
- 19.Find the value of x² − y² when x = 13 and y = 4.
- 20.Use (a − b)² = a² − 2ab + b² to find 75².
- 21.Find the value of x² − y² when x = 8 and y = 4.
- 22.If a + b = 3 and ab = 2, what is a² + b²?
- 23.Use (a − b)² = a² − 2ab + b² to find 47².
- 24.If a − b = 4 and ab = 5, what is a² + b²?
- 25.Use a² − b² = (a + b)(a − b) to find 56² − 48².
- 26.Find the value of x² − y² when x = 3 and y = 1.
- 27.Find the value of x² + 2xy + y² when x = 7 and y = 4.
- 28.Use (a + b)(a − b) = a² − b² to find 66 × 54.
- 29.If a − b = 1 and ab = 72, what is a² + b²?
- 30.If a + b = 14 and ab = 24, what is a² + b²?
- 31.Use (a + b)(a − b) = a² − b² to find 109 × 91.
- 32.Use a² − b² = (a + b)(a − b) to find 66² − 61².
- 33.Use (a + b)² = a² + 2ab + b² to find 29².
- 34.Use (a + b)² = a² + 2ab + b² to find 95².
- 35.Use (a + b)² = a² + 2ab + b² to find 32².
- 36.Use (a − b)² = a² − 2ab + b² to find 44².
- 37.Use (a + b)(a − b) = a² − b² to find 55 × 45.
- 38.Use (a − b)² = a² − 2ab + b² to find 24².
- 39.Use (a + b)(a − b) = a² − b² to find 102 × 98.
- 40.If a + b = 8 and ab = 12, what is a² + b²?
Answer key
- 169
- 146
- 896
- 1584
- 121
- 148
- 100
- 50
- 836
- 10609
- 1681
- 6399
- 25
- 5
- 4624
- 1521
- 2401
- 25
- 153
- 5625
- 48
- 5
- 2209
- 26
- 832
- 8
- 121
- 3564
- 145
- 148
- 9919
- 635
- 841
- 9025
- 1024
- 1936
- 2475
- 576
- 9996
- 40
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets