Identity VI and VII

Last updated at April 16, 2024 by

We will do questions of these identities

  • Identity VI - (a + b) 3 = a 3 + b 3 + 3ab(a + b)
  • Identity VII -  (a − b) 3 = a 3 - b 3 - 3ab(a - b)

 

Check Algebra Formulas for full list of formulas

 

Lets take an example

Identity VI - (a + b) 3 = a 3 + b 3 + 3ab(a + b)

(2 + 3) 3 = 2 3 + 3 3 + 3(2)(3) (2 + 3)

(5) 3 = 8 + 27 + 18 × 5

125 = 8 + 27 + 90

125 = 125

 

Identity VII -  (a − b)3 = a3 - b3 - 3ab(a - b)

(2 – 3)3 = 23 – 33 – 3(2)(3) (2 – 3)

(–1)3 = 8 – 27 – 18 × (–1)

–1 = 8 – 27 + 18

–1 = 26 – 27

–1 = –1

 

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo