Răspuns:
Explicație pas cu pas:
a=1/2+2/3+3/4+4/5+5/6+6/7
b=1/2+ 1/3 +1/4+ 1/5+ 1/6+ 1/7
....................................................... adunam primul termen a+primul termen b .....
a+b=(1/2+1/2)+(2/3+1/3).....+(6/7+1/7)=6x1=6
a+2004+b=2004+6=2010 ∈N
