Distributivity means

  a × (b + c) = ab + bc

  a × (b − c) = ab − bc

 

Example:

2 × (5 + 7)

= 2 × 5 + 2 × 7

= 10 + 14

= 24

 

2 × (5 − 7)

= 2 × 5 − 2 × 7

= 10 − 14

= −4

 

 2/3 × (5/6 - 9/6)

= (2/3 × 5/6) - (2/3 × 9/6)

= ((2 × 5)/(3 × 6)) - ((2 × 9)/(3 × 6))

= 10/18 - 18/18

= (10 - 18)/18  

= (-8)/18

= (-4)/9

2 × (9/8 + 4/8)

= (2 × 9/8) + (2 × 4/8)

= 9/4 + 4/4

= (9 + 4)/4

= 13/4

  1. Chapter 1 Class 8 Rational Numbers
  2. Concept wise

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.