Question

（1+1/1997+1/1999+1/2001)×(1/1997+1/1999+1/2001+1/2003)-(1+1/

Answer 1

设1/1997+1/1999+1/2001=A

原式=(1+A)×(A+1/2003)-(1+A+1/2003)×A

=(A+1/2003)+A×(A+1/2003)-A-(A+1/2003)×A

=1/2003