( 1 + 3 + 5 + 7 +... + 2003 + 2005 ) x ( 125125 x 127 - 127127 x 125 )

= ( 1 + 3 + 5 + 7 + ... + 2003 + 2005 ) x ( 125 x 1001 x 127 - 127 x 1001 x 125 )

= ( 1 + 3 + 5 + 7 + ... + 2003 + 2005 ) x 0

= 0

________________
 

(1999×1998+1998+1997)×(1/1+1/2:3/2-4/3)

= (1999×1998+1998+1997)×(1/1+1/2×2/3-4/3)

= 1999×1998+1998+1997)×(1/1+1/3-4/3)

= (1999×1998+1998+1997)×(4/3-4/3)

= (1999×1998+1998+1997)×0

= 0