原式=
20032002 2
20032001 2 + 20032003 2 -2 =
20032002 2
20032000×20032002+20032002×20032004 =
20032002 2
20032002(20032000+20032004) =
20032002 2
20032002×20032002×2 =
1
2 .
原式=
20032002 2
20032001 2 + 20032003 2 -2 =
20032002 2
20032000×20032002+20032002×20032004 =
20032002 2
20032002(20032000+20032004) =
20032002 2
20032002×20032002×2 =
1
2 .