Question

Tính giá trị biểu thức:

  A = 1 − 1 1.2 + 1 − 1 2.3 + ... + 1 − 1 2015.2016

Answer 1

  A = 1 − 1 1.2 + 1 − 1 2.3 + ... + 1 − 1 2015.2016         = 1 + 1 + 1 + ...1 − 1 1.2 + 1 2.3 + ... + 1 2015.2016         = 2015 − 1 − 1 2 + 1 2 − 1 3 + 1 3 − 1 4 + ... + 1 2015 − 1 2016         = 2015 − 1 − 1 2016         = 2015 − 1 + 1 2016         = 2014 + 1 2016         = 4060225 2016