Va rog,stie cnv cum se rezolva aceasta problemă?
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a-2b =3/2+4/3+5/4+...+2009/2008-2*1/2(1/2+1/3+1/4+...+1/2008)
= 3/2+4/3+5/4+...+2009/2008-1/2-1/3-1/4-...-1/2008
= 3/2-1/2+4/3-1/3+5/4-1/4+...+2009/2008-1/2008
= 2/2+3/3+4/4+...+2008/2008
= 1+1+1+...+1 ( de 2007 ori)
= 2007