Răspuns:
Explicație pas cu pas:
b - a = 2/1 + 3/2 + 4/3 + ... + 2013/2012 - 1/1 - 1/2 - 1/3 - ... - 1/2012
= (2/1 - 1/1) + (3/2 - 1/2) + (4/3 - 1/3) + ... + (2013/2012 - 1/2012)
= 1/1 + 2/2 + 3/3 + ... + 2012/2012
= 1 + 1 + 1 +... + 1
= 2012
