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ShortChallenge Level Yellow star
  • Problem
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When proving an identity it is usually best to start with the more complicated expression and simplify it so this time start with the expression on the right hand side $(k+1)! - k!$. 

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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