分子=1+2+3+4+5+6+5+4+3+2+1
=2(1+2+3+4+5)+6
=30+6
=36
原式=36/6666×6666
=36/(6666×6666)
=(6*6)/(6*1111*6*1111)
=1/(1111*1111)
=1/1 234 321
分子=1+2+3+4+5+6+5+4+3+2+1
=2(1+2+3+4+5)+6
=30+6
=36
原式=36/6666×6666
=36/(6666×6666)
=(6*6)/(6*1111*6*1111)
=1/(1111*1111)
=1/1 234 321